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Structural and Energetic Aspects of Entacapone-Theophylline-Water Cocrystal
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Thermoelectric Properties of Pnma and Rocksalt SnS and SnSe
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Evaluation of the Molecular Conformation of Surface Alkyl Chains of Alkylsilane-Derived Hybrid Films Using Sum-Frequency Generation Spectroscopy
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Raman Studies of Lattice of FAPbBr3 and MAPbBr3 Perovskites
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Calculation of the Localized Surface Plasmon Resonances of Au Nanoparticles Embedded in NiO
Journal Description
Solids
Solids
is an international, peer-reviewed, open access journal on all areas of solid-state sciences published quarterly online by MDPI.
- Open Access—free to download, share, and reuse content. Authors receive recognition for their contribution when the paper is reused.
- High Visibility: indexed within CAPlus / SciFinder, and many other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision provided to authors approximately 15.5 days after submission; acceptance to publication is undertaken in 4.6 days (median values for papers published in this journal in the second half of 2021).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
Latest Articles
Vibrational Enthalpies of Solid Crystalline Materials
Solids 2022, 3(2), 319-326; https://doi.org/10.3390/solids3020023 - 24 May 2022
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Specific heat at constant pressure is traditionally a difficult thermodynamic quantity to obtain from first-principles calculations. While theoretical avenues to do exist—most notably, the quasi-harmonic approximation—there are many materials for which this approximation is not valid. One of
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Specific heat at constant pressure is traditionally a difficult thermodynamic quantity to obtain from first-principles calculations. While theoretical avenues to do exist—most notably, the quasi-harmonic approximation—there are many materials for which this approximation is not valid. One of those materials is Ge. In this paper, we demonstrate how a new method—termed the Beyond Quasi-Harmonic method—takes into account all anharmonic vibrations by showing how our results are significantly better than those achieved through using the quasi-harmonic model. In addition, we calculate for 3C-SiC, a material for which there are surprisingly few experimental results. For 3C-SiC, our results agree well with the available experiments, and for Ge, our results agree very well with the generally accepted values.
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Effective Method for Multi-Probe Electrical Measurements of Organic Single Crystals: Four-Terminal Natural Adhesion Contact
Solids 2022, 3(2), 311-318; https://doi.org/10.3390/solids3020022 - 19 May 2022
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A technique to establish electrical contact and perform multi-probe electrical measurements (e.g., four-probe measurements), even at low temperatures, is presented in this work. The natural adhesion contact (NAC) is applicable to the wide range of dimensions of organic crystals. Furthermore, the precise electrode
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A technique to establish electrical contact and perform multi-probe electrical measurements (e.g., four-probe measurements), even at low temperatures, is presented in this work. The natural adhesion contact (NAC) is applicable to the wide range of dimensions of organic crystals. Furthermore, the precise electrode patterns required to carry out multi-probe measurements are guaranteed, in contrast to fine conductive paste painting methods. We demonstrate four-probe electrical measurements of -(BEDT-TTF) I (where BEDT-TTF = bis(ethylenedithio) tetrathiafulvalene) at temperatures down to 100 K. The obtained temperature dependence showed a steep meta l–insulator transition and exhibited zero hysteresis throughout several measurement sequences.
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Effect of Vanadium Catalysts on Hydrogen Evolution from NaBH4
Solids 2022, 3(2), 295-310; https://doi.org/10.3390/solids3020021 - 18 May 2022
Abstract
NaBH4 is a very cheap and hydrogen-rich material, as well as a potential hydrogen store. However, the high temperature of its thermal decomposition (above 530 °C) renders it inapplicable in practical use. Here, we studied the effect of addition of diverse V-containing
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NaBH4 is a very cheap and hydrogen-rich material, as well as a potential hydrogen store. However, the high temperature of its thermal decomposition (above 530 °C) renders it inapplicable in practical use. Here, we studied the effect of addition of diverse V-containing catalysts on thermal hydrogen desorption. It turns out that mechanochemical doping of NaBH4 with vanadium metal, its oxides, or nanoparticles lowers the temperature of pyrolysis significantly. Notably, NaBH4 milled for 3 h with 25 wt.% V2O5 or VO2 releases ca. 70% of stored hydrogen in the temperature range of ca. 370–450 °C. On the other hand, precursors and solvents used to prepare rather uniform vanadium nanoparticles (~4 nm) suspended in THF or less uniform and larger ones (~15 nm) in o- difluorobenzene have adverse effect on the purity of hydrogen evolved.
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Numerical Simulation of Particle-Laden Flow and Soot Layer Formation in Porous Filter
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Solids 2022, 3(2), 282-294; https://doi.org/10.3390/solids3020020 - 10 May 2022
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So far, diesel particulate filters (DPFs) have been widely used to collect diesel particulates including soot in the exhaust after-treatment. However, as the soot is continuously collected in the porous filter, the exhaust pressure (pressure drop) increases. To optimize the filter design for
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So far, diesel particulate filters (DPFs) have been widely used to collect diesel particulates including soot in the exhaust after-treatment. However, as the soot is continuously collected in the porous filter, the exhaust pressure (pressure drop) increases. To optimize the filter design for reducing its pressure drop, we need a numerical simulation. In this study, we simulated the particle-laden flow across the DPF. Structure of SiC-DPF was obtained by an X-ray CT technique. We conducted the numerical simulation by changing the soot aggregation diameter (simply called soot size), and evaluated the time-variation of the pressure drop. For discussing the soot deposition process, the contributions of the Brownian diffusion and the interception effect were separately estimated. Especially, we focused on the soot deposition region which could affect the pressure drop, together with the soot cake permeability and the soot packing density. Results show that, as the soot size is smaller, more soot is trapped. As a result, the shift from the depth filtration to the surface filtration is observed earlier. Therefore, for discussing the pressure drop, it is important to consider where the soot deposition occurs as well as the deposited soot mass in the filter.
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Open AccessArticle
Deposition of Organic-Inorganic Nanocomposite Coatings for Biomedical Applications
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and
Solids 2022, 3(2), 271-281; https://doi.org/10.3390/solids3020019 - 06 May 2022
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Polymethylmethacrylate (PMMA) is a material of choice for many biomedical coating applications. However, such applications are limited due to the toxicity of the traditional solvents used for the solution processing of PMMA coatings and composites. This problem is addressed using an isopropanol-water co-solvent,
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Polymethylmethacrylate (PMMA) is a material of choice for many biomedical coating applications. However, such applications are limited due to the toxicity of the traditional solvents used for the solution processing of PMMA coatings and composites. This problem is addressed using an isopropanol-water co-solvent, which allows for the dissolution of high molecular mass PMMA and the fabrication of coatings by a dip-coating method from concentrated PMMA solutions. The use of the co-solvent offers a versatile strategy for PMMA solubilization and coating deposition, despite the insolubility of PMMA in water and isopropanol. Composite coatings are obtained, containing hydroxyapatite, silver oxide, zinc oxide, micron size silica and nanosilica. Such coatings are promising for the manufacturing of implants with enhanced biocompatibility, bioactivity and antimicrobial properties and the fabrication of biosensors. Ibuprofen, tetracycline and amoxicillin are used as model drugs for the fabrication of PMMA-drug composite coatings for drug delivery. The microstructure and composition of the coatings are analyzed. The versatile dip-coating method of this investigation provides a platform for various biomedical applications.
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Investigation of the Tetrakis(dimethylamino)hafnium and H2S ALD Process: Effects of Deposition Temperature and Annealing
Solids 2022, 3(2), 258-270; https://doi.org/10.3390/solids3020018 - 05 May 2022
Abstract
HfS2 has recently emerged as a promising 2D semiconductor, but the lack of a reliable method to produce continuous films on a large scale has hindered its spreading. The atomic layer deposition of the material with the precursor tetrakis-dimethylamino-hafnium with H2
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HfS2 has recently emerged as a promising 2D semiconductor, but the lack of a reliable method to produce continuous films on a large scale has hindered its spreading. The atomic layer deposition of the material with the precursor tetrakis-dimethylamino-hafnium with H2S is a relatively novel solution to this problem. This paper shows that it is a facile approach to synthesizing homogeneous and smooth HfS2 layers in a controlled and reproducible manner. The deposition is examined at different temperatures and layer thicknesses, exploring the ALD window of the deposition and the chemical, morphological and electronic properties of the films. The method yielded films with wafer-sized uniformity and controlled properties and is, thus, a promising way to prepare this important transition metal dichalcogenide material.
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Composites of (C4F)n and (CF)n Synthesized by Uncatalyzed Fluorination of Graphite
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, , , , , and
Solids 2022, 3(2), 237-257; https://doi.org/10.3390/solids3020017 - 29 Apr 2022
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A new solid-state F magic-angle spinning NMR signal at an isotropic F chemical shift of −53 ppm is measured from graphite fluoride synthesized by reaction of graphite with F at temperatures above 750 K with no catalyst. Two-dimensional NMR suggests
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A new solid-state F magic-angle spinning NMR signal at an isotropic F chemical shift of −53 ppm is measured from graphite fluoride synthesized by reaction of graphite with F at temperatures above 750 K with no catalyst. Two-dimensional NMR suggests the −53 ppm F NMR signal originates from covalent fluoromethanetriyl groups belonging to ordered (C F) bulk domains composited with the major (CF) domains. Quantitative F and C NMR find . DFT calculations of NMR chemical shifts for unsaturated fluorographene models show that a (C F) phase with fluorine bound covalently to a single side of the carbon layer best explains the observed NMR chemical shifts. We assign the new phase to this (C F) structure, which constitutes up to 15% of the carbon in our graphite fluoride composites. The (C F) content of the composite affects bulk electrochemical properties in a manner similar to graphite fluorides produced by conventional, catalyzed fluorination processes.
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Open AccessArticle
Fine Structure of the Carbon-Related Blue Luminescence Band in GaN
Solids 2022, 3(2), 231-236; https://doi.org/10.3390/solids3020016 - 26 Apr 2022
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Photoluminescence studies reveal three CN-related luminescence bands in GaN doped with carbon: the YL1 band at 2.17 eV caused by electron transitions via the −/0 level of the CN, the BLC band at 2.85 eV due to transitions
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Photoluminescence studies reveal three CN-related luminescence bands in GaN doped with carbon: the YL1 band at 2.17 eV caused by electron transitions via the −/0 level of the CN, the BLC band at 2.85 eV due to transitions via the 0/+ level of the CN and the BL2 band at 3.0 eV attributed to the CNHi complex. The BLC band studied here has the zero-phonon line at 3.17 eV and a phonon-related fine structure at low temperatures. The 0/+ level of the CN is found at 0.33 ± 0.01 eV above the valence band, in agreement with recent theoretical predictions. These results will help to choose an optimal correction scheme in hybrid functional calculations.
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A Molecular Dynamics Study of Tungsten’s Interstitial Dislocation Loops Formation Induced by Irradiation under Local Strain
Solids 2022, 3(2), 219-230; https://doi.org/10.3390/solids3020015 - 18 Apr 2022
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A molecular dynamics simulation was used to investigate the effect of applied strain on the formation of primary defects and the probability of interstitial dislocation loops (IDLs) formation of tungsten (W) during a collision cascade event. The research investigated primary knock-on atom energies
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A molecular dynamics simulation was used to investigate the effect of applied strain on the formation of primary defects and the probability of interstitial dislocation loops (IDLs) formation of tungsten (W) during a collision cascade event. The research investigated primary knock-on atom energies of 1, 6, 10, and 14 keV, applied on a deformed W structure (form −1.4~1.6%). The peak and surviving number of Frenkel pairs (FPs) increased with increasing tension; however, these increases were more pronounced under higher strain due to the formation of IDLs. For 10 self-interstitial atoms (SIA) lengths, the strain effect reduces the clustering energy of the IDLs by about 7 eV. In general, the current findings suggest that strain effects should be carefully considered in radiation-damaged environments, particularly in low-temperature, high-radiation-energy environments. The compressed condition may advantage materials used in high-radiation-damage devices and power systems.
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An Electron Waveguide Model for FDSOI Transistors
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Solids 2022, 3(2), 203-218; https://doi.org/10.3390/solids3020014 - 15 Apr 2022
Abstract
We extend our previous semi-empirical model for quantum transport in a conventional nano-MOSFET to FDSOI transistors. In ultra-thin-body and -BOX (UTBB) FDSOI transistors, the electron channel can be treated as an electron waveguide. In the abrupt transition approximation, it is possible to derive
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We extend our previous semi-empirical model for quantum transport in a conventional nano-MOSFET to FDSOI transistors. In ultra-thin-body and -BOX (UTBB) FDSOI transistors, the electron channel can be treated as an electron waveguide. In the abrupt transition approximation, it is possible to derive an analytical approximation for the potential seen by the charge carriers. With these approximations we calculate the threshold voltage and the transfer characteristics, finding remarkably good agreement with experiments in the OFF-state given the relative simplicity of our model. In the ON-state, our theory fails because Coulomb interaction between the free charge carriers and the device heating is neglected in our approach.
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Low-Cost Surface Enhanced Raman Scattering for Bio-Probes
Solids 2022, 3(2), 188-202; https://doi.org/10.3390/solids3020013 - 07 Apr 2022
Abstract
Raman Spectroscopy is a well-known method for identifying molecules by their spectroscopic “fingerprint”. In Surface Enhanced Raman Scattering (SERS), the presence of nanometallic surfaces in contact with the molecules enormously enhances the spectroscopic signal. Raman enhancing surfaces are often fabricated lithographically or chemically,
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Raman Spectroscopy is a well-known method for identifying molecules by their spectroscopic “fingerprint”. In Surface Enhanced Raman Scattering (SERS), the presence of nanometallic surfaces in contact with the molecules enormously enhances the spectroscopic signal. Raman enhancing surfaces are often fabricated lithographically or chemically, but the throughput is low and the equipment is expensive. In this work a SERS layer was formed by the self-assembly of silver nanospheres from a hexane suspension onto an imprinted thermoplastic sheet (PET). In addition, the SERS layer was transferred and securely bonded to other surfaces. This is an important attribute for probes into solid specimen. Raman spectra were obtained with Rhodamine 6G (R6G) solution concentrations ranging from 1 mm to 1 nm. The methods described here produced robust and sensitive SERS surfaces with inexpensive equipment, readily available materials, and with no chemical or lithographic steps. These may be critical concerns to laboratories faced with diminishing funding resources.
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(This article belongs to the Topic Synthesis and Applications of Nanostructured Metals and Metal Oxides)
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Migration Barrier Estimation of Carbon in Lead for Lead–Acid Battery Applications: A Density Functional Theory Approach
Solids 2022, 3(2), 177-187; https://doi.org/10.3390/solids3020012 - 22 Mar 2022
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Recent efforts towards developing novel lead electrodes involving carbon and lead composites have shown potential for increasing the cycle life of lead–acid (LA) batteries used to store energy in various applications. In this study, first-principles calculations are used to examine the structural stability,
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Recent efforts towards developing novel lead electrodes involving carbon and lead composites have shown potential for increasing the cycle life of lead–acid (LA) batteries used to store energy in various applications. In this study, first-principles calculations are used to examine the structural stability, defect formation energy, and migration barrier of C in Pb for LA batteries. Density functional theory with the GGA-PBE functional performed the best out of various functionals used for structural stability calculations. Furthermore, with the complete incorporation of C in the Pb matrix, the results show that C is energetically preferred to be at the octahedral interstitial ( ) site in the FCC structure of Pb. Additionally, climbing-image nudged elastic band calculations show a minimum energy pathway for C diffusing from a stable octahedral site to the adjacent octahedral site assisted by a tetrahedral intermediate site. Therefore, the minimum energy pathway for C migration is envisioned to be , where the total energy barrier is observed to be ~90% and more than 100% lower than the and barriers, respectively.
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Thermoelectric Properties of Pnma and Rocksalt SnS and SnSe
Solids 2022, 3(1), 155-176; https://doi.org/10.3390/solids3010011 - 17 Mar 2022
Abstract
Thermoelectric materials convert waste heat to electricity and are part of the package of technologies needed to limit global warming. The tin chalcogenides SnS and SnSe are promising candidate thermoelectrics, with orthorhombic SnSe showing some of the highest figures of merit
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Thermoelectric materials convert waste heat to electricity and are part of the package of technologies needed to limit global warming. The tin chalcogenides SnS and SnSe are promising candidate thermoelectrics, with orthorhombic SnSe showing some of the highest figures of merit reported to date. As for other Group IV chalcogenides, SnS and SnSe can form rocksalt phases under certain conditions, but the thermoelectric properties of these phases are largely unexplored. We have applied a fully ab initio modelling protocol to compare the of the orthorhombic and rocksalt phases of SnS and SnSe. Electronic structures from hybrid density-functional theory were used to calculate the three electrical transport properties, including approximate models for the electron relaxation times, and lattice dynamics calculations were performed to model the phonon spectra and lattice thermal conductivities. We obtained good estimates of the of the well-studied orthorhombic phases. The rocksalt phases were predicted to show larger electrical conductivities and similar Seebeck coefficients to the orthorhombic phases, resulting in higher thermoelectric power factors, but these were offset by larger thermal conductivities. These results therefore motivate further investigation of the recently discovered “ -cubic” phases of SnS and SnSe, which are based on distorted rocksalt supercells, to establish their thermoelectric performance.
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(This article belongs to the Special Issue Feature Papers of Solids 2021)
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Evaluation of the Molecular Conformation of Surface Alkyl Chains of Alkylsilane-Derived Hybrid Films Using Sum-Frequency Generation Spectroscopy
Solids 2022, 3(1), 147-154; https://doi.org/10.3390/solids3010010 - 17 Mar 2022
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Alkylsilane-derived hybrid films exhibiting excellent dynamic dewetting behaviors toward various liquids are promising, since they are smooth, highly transparent, and a low environmental burden. However, the detailed mechanism of their unique dynamic dewetting behaviors and its relation to the surface segregation of alkylsilanes
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Alkylsilane-derived hybrid films exhibiting excellent dynamic dewetting behaviors toward various liquids are promising, since they are smooth, highly transparent, and a low environmental burden. However, the detailed mechanism of their unique dynamic dewetting behaviors and its relation to the surface segregation of alkylsilanes during the film formation have not yet been clearly identified. In this study, we prepared various hybrid films by varying the mixing ratios of tetraethoxysilane (TEOS) and n-dodecyltriethoxysilane (C12TES) and investigated the changes in the s-CH2/s-CH3 peak strength ratios of the resulting hybrid films under dry and wet conditions by sum-frequency generation (SFG) spectroscopy. When the static/dynamic water contact angles significantly changed, it was clearly observed that the s-CH2/s-CH3 ratio of each hybrid film under dry and wet condition also changed markedly. With increasing TEOS concentration, the static contact angles became smaller, while the contact angle hysteresis tended to increase because of the increase in gauche defects at the air interface and hydrogen bonds. This finding suggests that the concentration and conformation of the alkyl chains derived from surface-segregated C12TES molecules play an important role in determining the final dewetting behaviors of the hybrid films to water.
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Open AccessReview
Surface Plasmons Excited by X-rays in the Surface Layers of Solids
Solids 2022, 3(1), 122-146; https://doi.org/10.3390/solids3010009 - 01 Mar 2022
Abstract
The phenomenon of total external reflection of X-rays at a sliding angle of incidence of a beam of incident X-rays is investigated. For metals, a quantitative law of direct dependence of the refractive index decrement on the interplane distance is obtained. The excitation
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The phenomenon of total external reflection of X-rays at a sliding angle of incidence of a beam of incident X-rays is investigated. For metals, a quantitative law of direct dependence of the refractive index decrement on the interplane distance is obtained. The excitation of surface plasmons by X-rays that have experienced complete external reflection is detected. For surface plasmons, a dimensional effect was observed, expressed in an increase in the energy of plasmons and the concentration of conduction electrons with an increase in the depth of the output of surface plasmons. By the method of dispersion of surface plasmons, internal mechanical micro-stresses and spontaneous polarization of the surface layers of glassy dielectrics and in thin layers of vanadium dioxide were determined. The absence of micro-stresses in the lithium fluoride ionic single crystal was found out, and the polarization observed in it is due to the large dipole moment of the molecules of this crystal. In thin films of vanadium dioxide, the dependence of micro-stresses on the stresses in the substrates was found.
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Open AccessFeature PaperArticle
Temperature-Dependent Raman Studies of FAPbBr3 and MAPbBr3 Perovskites: Effect of Phase Transitions on Molecular Dynamics and Lattice Distortion
by
and
Solids 2022, 3(1), 111-121; https://doi.org/10.3390/solids3010008 - 19 Feb 2022
Cited by 1
Abstract
Three-dimensional hybrid organic–inorganic lead halide perovskites are promising photovoltaic and light-emitting materials. A key phenomenon relevant for their optoelectronic applications is electron–phonon coupling. Since it can be strongly modified by structural deformation and changes in the dynamics of molecular cations, it is of
[...] Read more.
Three-dimensional hybrid organic–inorganic lead halide perovskites are promising photovoltaic and light-emitting materials. A key phenomenon relevant for their optoelectronic applications is electron–phonon coupling. Since it can be strongly modified by structural deformation and changes in the dynamics of molecular cations, it is of great importance to study the temperature dependence of phonon properties of hybrid perovskites. In this work, temperature-dependent Raman scattering studies of FAPbBr3 and MAPbBr3 single crystals are reported in the 1800–22 cm−1 and 300–90 K ranges. The Raman data of MAPbBr3 showed clear anomalies near 236, 155 and 148 K, which were attributed to →I4/mcm→P4/mmm (or Imma)→Pnma phase transitions. They also provided strong evidence that crystal structure of the phase stable in the 155–148 K range is very similar to structure of the I4/mcm phase, not structure of the lowest-temperature Pmna phase, as suggested in some reports. Therefore, the symmetry of this phase seems to be more likely P4/mmm rather than Imma. An analysis of the temperature evolution of MAPbBr3 Raman modes revealed that the phase transitions near 236 and 155 K are associated with weak distortion of the inorganic subnetwork and changes in the dynamics of MA+ ions. Very pronounced changes in the lattice modes region and a narrowing of bands below 148 K indicated that the phase transition to the Pnma phase is triggered by a freezing of MA+ motions, which in turn leads to strong distortion of the inorganic subnetwork. Raman studies of FAPbBr3 showed that this material behaves in a very different way than MAPbBr3. First of all, the molecular dynamics of FA+ cations are not frozen even in the lowest-temperature Pnma phase. Moreover, the distortion of the inorganic subnetwork is small in the Pnma phase. The observation of weak anomalies in the lattice modes region confirmed, however, that the two crystallographically resolved phase transitions ( →P4/mbm near 260 K and P4/mbm→Pnma near 150 K) lead to weak distortion of the inorganic subnetwork. On the other hand, an analysis of FA+ internal modes indicated that these transitions, as well as two other crystallographically unresolved transitions near 120 and 180 K, are triggered by a change of FA+ dynamics.
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Thirty-Year Anniversary of κ-(BEDT-TTF)2Cu2(CN)3: Reconciling the Spin Gap in a Spin-Liquid Candidate
Solids 2022, 3(1), 93-110; https://doi.org/10.3390/solids3010007 - 17 Feb 2022
Cited by 1
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In 1991 the layered organic compound -(BEDT-TTF) Cu (CN) with a triangular lattice was synthesized for the first time. Although, originally, the focus was on the superconducting properties under pressure, this frustrated Mott insulator has been the most promising
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In 1991 the layered organic compound -(BEDT-TTF) Cu (CN) with a triangular lattice was synthesized for the first time. Although, originally, the focus was on the superconducting properties under pressure, this frustrated Mott insulator has been the most promising quantum-spin-liquid candidate for almost two decades, widely believed to host gapless spin excitations down to . The recent observation of a spin gap rules out a gapless spin liquid with itinerant spinons and puts severe constraints on the magnetic ground state. This review evaluates magnetic, thermal transport, and structural anomalies around K. The opening of a spin gap yields a rapid drop of spin susceptibility, NMR Knight shift, spin-lattice relaxation rate, and -SR spin fluctuation rate, but is often concealed by impurity spins. The concomitant structural transition at manifests in thermal expansion, THz phonons and Cu NQR relaxation. Based on the field dependence of , a critical field of 30–60 T is estimated for the underlying spin-singlet state. Overall, the physical properties are remarkably similar to those of spin-Peierls compounds. Thus, a strong case is made that the ‘6K anomaly’ in -(BEDT-TTF) Cu (CN) is the transition to a valence-bond-solid state and it is suggested that such a scenario is rather the rule than the exception in materials with strong magnetic frustration.
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Structural and Energetic Aspects of Entacapone-Theophylline-Water Cocrystal
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, , , , , , and
Solids 2022, 3(1), 66-92; https://doi.org/10.3390/solids3010006 - 10 Feb 2022
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Pharmaceutical cocrystals are currently gaining interest among the scientific community, due to their great potential for providing novel crystalline forms with superior properties such as solubility, dissolution rate, bioavailability, and stability. Robust computational tools are valuable tools in the rationalization of cocrystal formation,
[...] Read more.
Pharmaceutical cocrystals are currently gaining interest among the scientific community, due to their great potential for providing novel crystalline forms with superior properties such as solubility, dissolution rate, bioavailability, and stability. Robust computational tools are valuable tools in the rationalization of cocrystal formation, by providing insight into the intermolecular interactions of multicomponent molecular solids. In this study, various computational techniques based on charge density analysis were implemented to assess structural and energetical perspectives of the interactions responsible for the formation and stability of entacapone-theophylline-water (ETP-THP-water, 1:1:1). Significant non-covalent interactions (NCIs) were identified and evaluated by Hirshfeld surface analysis and density functional theory (DFT) computations, and three-dimensional networks (energy vector diagrams, lattice energy frameworks) were constructed, outlining the crucial stabilizing role of water and the dominance of π-π stacking interactions in the cocrystal. Furthermore, thermal dehydration studies confirmed the strong binding of water molecules in the crystal lattice, as expressed by the high activation energy.
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Open AccessArticle
Calculation of the Localized Surface Plasmon Resonances of Au Nanoparticles Embedded in NiO
by
, , , , and
Solids 2022, 3(1), 55-65; https://doi.org/10.3390/solids3010005 - 28 Jan 2022
Abstract
The present article examined the influence of size and periodicity of simulated gold (Au) nanoparticles (NPs) embedded in Nickel Oxide (NiO) matrix on localized plasmonic resonances (LSPRs). The scope of this work is to comparatively study the theoretical outcomes exhibited against the experimental
[...] Read more.
The present article examined the influence of size and periodicity of simulated gold (Au) nanoparticles (NPs) embedded in Nickel Oxide (NiO) matrix on localized plasmonic resonances (LSPRs). The scope of this work is to comparatively study the theoretical outcomes exhibited against the experimental results delivered from previous works, including a significant number of simulations and testing of numerous NPs diameter values. A comparison between Au and NiO NPs over silver (Ag) and NiO NPs is also reported to investigate whether the nature of noble metal affects its behavior in terms of LSPRs. The computational results strongly support that the appearance and intensity of LSPRs is straightforward to the increase in the diameter of NPs. The simulation results are in a good agreement with the literature of small NPs, offering the opportunity to further understand the LSPR phenomenon and its more effective implementation to opto-electronic applications. Rigorous Coupled Wave Analysis (RCWA) is performed to stimulate the justification and knowledge of the theoretical conclusions.
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[email protected] Composites with Potential Antifouling Properties for Open-Environment Applications of Metal-Organic Frameworks
by
, , , , and
Solids 2022, 3(1), 35-54; https://doi.org/10.3390/solids3010004 - 27 Jan 2022
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Metal-organic frameworks (MOFs) are promising materials for a myriad of applications because of their easy synthesis and large variability through the organic linker. For open-environment applications, the organic content can, however, give rise to fouling, that is, biofilm formation. Biofilms can destroy the
[...] Read more.
Metal-organic frameworks (MOFs) are promising materials for a myriad of applications because of their easy synthesis and large variability through the organic linker. For open-environment applications, the organic content can, however, give rise to fouling, that is, biofilm formation. Biofilms can destroy the MOF and reduce the sorption capacity. Therefore, it is necessary to formulate MOFs for open-environment application to avoid the growth of microorganisms. Chitosan is a polysaccharide biopolymer, obtained from chitin shells of shrimps by alkaline deacetylation, and has known fungistatic properties. Here, chitosan is used as a matrix for [email protected] composites with different aluminum-based MOFs to implement the fungistatic effect of chitosan to MOFs. The obtained composites with the highest possible MOF loadings of up to 90% were tested according to DIN EN ISO 846 to examine the fungistatic material properties against the fungi Chaetomium globosum and Aspergillus falconensis.
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Topic Editors: Damian Przestacki, Michal Kulka, Wensheng LiDeadline: 20 September 2022
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Chemistry, Molecules, Nanomaterials, Solids
Advances in Inorganic Mechanochemistry for Applications in Materials Science
Topic Editors: Matej Baláž, Abhishek Lokhande, Marcela AchimovičováDeadline: 31 December 2022
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Applied Sciences, Nanomaterials, Solids, Sensors, Chemosensors
Synthesis and Applications of Nanostructured Metals and Metal Oxides
Topic Editors: Ki-Hyun Kim, Deepak KukkarDeadline: 31 January 2023

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Glass-Ceramics: A Key Technology for Advanced Engineering Applications
Guest Editor: Enrico BernardoDeadline: 31 October 2022
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Composite Soft Materials in Separation Processes, Molecular Recognition and Delivery
Guest Editors: Gianluca Di Profio, Elvira PantusoDeadline: 31 December 2022
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Solids in Europe
Guest Editors: Mirosław Mączka, Juan B. Carda CastellóDeadline: 31 January 2023