Special Issue "High-Pressure Studies of Crystalline Materials"
Deadline for manuscript submissions: 20 March 2018
High-pressure research has seen a great progress during the last few decades as a consequence of the combined development of various experimental techniques and computer simulations. Recently, the number of studies of crystalline materials under high pressure has growth exponentially and the pressure range covered by them has been extremely extended reaching magnitudes of the order of Terapascals. Important discoveries have been achieved thanks to high-pressure studies. These breakthroughs concerns different research fields including solid-state physics, chemistry, and materials science among others. Metallization of hydrogen is the most recent of them. The impact of pressure on chemical and physical properties and some of the contemporary discoveries are the main reasons for producing the current Special Issue.
The Special Issue on “High-Pressure Studies of Crystalline Materials” pretends to give a forum aimed at describing and discussing recent results of high-pressure studies on structural, mechanical, vibrational, and electronic properties of crystalline materials. The intention is to give special emphasis to phase transitions and their effects on different properties, but other issues are not excluded. The Special Issue is open to both experimental and theoretical contributions. Researchers working in a wide range of disciplines are welcomed to contribute to it. The topics summarized under the keywords given below are just broadly examples of the greater number of topics in mind. The volume is especially open for any innovative contributions and also for brief reviews of current hot topics.Prof. Dr. Daniel Errandonea
Manuscript Submission Information
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.
Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.
- High pressure research
- Matter at extreme conditions
- Structural properties
- Vibrational and electronic properties
- Equation of state
- Phase transitions
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Title: Evolution of interatomic and intermolecular interactions and polymorphism of melamine at high pressure
Authors: Hannah Shelton (1,2), P. Dera (1,2), Y. Meng (3), S. Tkachev(4)
1 Hawaii Inst. of Geophysics and Planetology, Univ. of Hawaii at Mānoa, Honolulu, HI, USA
2 Department of Geology & Geophysics, Univ. of Hawaii at Mānoa, Honolulu, HI, USA
3 High Pressure Collaborative Access Team, Carnegie Inst. of Washington, Advanced Photon Source, Argonne National Laboratory, IL, USA
4 Center for Advanced Radiation Sources, Univ. of Chicago, Argonne National Laboratory, Chicago, IL, USA
Abstract: Melamine (C3H6N6; 1,3,5-triazine-2,4,6-triamine) is an aromatic ring molecule, with carbon and nitrogen atoms forming the ring body, and amine groups bonded to each carbon. Melamine is widely used to produce laminate products, adhesives, and flame retardants. However, melamine has a similar structure to several well-known explosives, including TATB and RDX. Additionally, melamine may be a precursor in the synthesis of superhard carbon-nitrides, such as β-C3N4. The superstructure of melamine forms corrugated sheets of individual melamine molecules, where kinked planes of molecules are stacked on top of one another, where individual melamine molecules are linked to others by intra- and inter-plane N-H hydrogen bonds. Several previous high pressure x-ray diffraction and Raman spectroscopy studies have claimed that melamine undergoes two or more phase transformation below 25 GPa. Our single crystal data demonstrate that melamine retains the ambient, monoclinic P21/a structure to nearly 40 GPa. At 37 GPa, the unit cell volume has decreased by more than a factor of two without significant chance in the molecular geometry, as the hydrogen bond distances between molecular units decrease. A phase transition to a triclinic structure, different than previously suggested, was found at approximately 40 GPa, with indications of amorphization beyond 45 GPa. Examining the effect hydrogen bonds have on melamine’s structure will allow it to be better utilized as a chemical feedstock and analog for related compounds.
Title: High-Pressure, high-temperature behavior of silicon carbide
Authors: Kierstin Daviau and Kanani K. M. Lee
Affiliation: Department of Geology & Geophysics, Yale University
Abstract: Silicon carbide (SiC), a hard, semi-conducting material commonly known for its many polytypes and refractory nature, has been the subject of many high-pressure studies in recent times. Through work done both experimentally and computationally, many interesting aspects of high-pressure SiC have been measured and explored. Considerable work has been done to measure the effect of pressure on the vibrational and material properties of SiC. Additionally, the transition from the low-pressure zinc-blende B3 structure to the high-pressure rocksalt B1 structure has been measured by several groups in both the diamond-anvil cell and shock communities, and has been predicted in numerous computational studies. Finally, high temperature studies have explored the thermal equation of state and thermal expansion of SiC, as well as the high-pressure and temperature melting behavior. From high-pressure phase transitions, phonon behavior, and melting characteristics, our increased knowledge of SiC is improving our understanding of its industrial uses, as well as opening up its application to other fields such as planetary science.
Title: Crystal structure of FeSe2 at high pressure and at low temperature
Authors: Barbara Lavina 1,*, Robert T. Downs 2 and Stanislaw Sinogeikin3
1 High Pressure Science and Engineering Center, University of Nevada, Las Vegas; email@example.com
2 Department of Geosciences, University of Arizona; firstname.lastname@example.org
3 HPCAT, Carnegie Institution of Washington; email@example.com
Abstract: Iron selenides are interesting compounds for their unique physical properties and as ore materials. In order to understand the response of these compounds to variable external conditions we investigated natural ferrosilite, FeSe2, under conditions of high pressure and of low temperature. The crystal structure analysis was performed with single-crystal x-ray microdiffraction. No evidences of structural instability were observed up to ~ 50 GPa at ambient temperature and down to ~ 50 K at ambient pressure. The deformation of the orthorhombic lattice is slightly anisotropic. The Se-Se dumbbell compressibility is marginally larger than that of the mixed Fe-Se bonds, we also observed a small increase of the FeSe6 octahedral distortion with load increase. The effects of cooling are small but qualitatively similar to those produced by pressure.
Title: Layered Indium Selenide under High Pressure: A Review
Author: Alfredo Segura
Affiliation: Departamento de Física Aplicada-ICMUV, Malta-Consolider Team, Universitat de València, 46100 Burjassot, Spain; Alfredo.Segura@uv.es
Abstract: This paper presents a short review of the research work done on the structural and electronic properties of layered Indium Selenide (InSe) and related III-VI semiconductors under high pressure conditions. The paper will mainly focus on the crucial role played by high pressure experimental and theoretical tools to investigate the electronic structure of InSe. This objective involves a previous revision of results on the pressure dependence of InSe crystal structure and related topics such as the equation of state and the pressure-temperature crystal phase diagram. The main part of the paper will be devoted to review the literature on the optical properties of InSe under high pressure, especially papers on absorption experiments that led to the identification of the main optical transitions, and their assignment to specific features of InSe electronic structure, with the help of modern first-principles band structure calculations. In connection with these achievements we will also review relevant results on lattice dynamical, dielectric and transport properties of InSe, as they provided very useful supplementary information on the electronic structure of the material.
Keywords: InSe; layered semiconductors; III-VI semiconductors; high pressure; optical properties; magnetoabsorption; electronic structure; lattice dynamics; dielectric properties; transport properties.
Title: High-pressure elastic, vibrational and structural study of monazite-type GdPO4 from ab initio simulations
Authors: Alfonso Muñoz, Plácida Rodríguez-Hernández
Affiliation: Instituto de Materiales y Nanotecnología, Departamento de Física, MALTA Consolider Team, Universidad de La Laguna, La Laguna, E-38205 Tenerife, Spain
Abstract: GdPO4 monazite-type has been studied under high pressure by first principles calculations in the framework of density functional theory. The study focuses on the structural, dynamical and elastic properties of this material. Results about the structure and its evolution under pressure, the equation of state and the compressibility are reported. The evolution of the Raman and Infrared frequencies, and their pressure coefficients are also presented. Finally, the study of the elastic constants allows to provide information related with the elastic properties of this compound.
Title: Growth of single crystal diamond in 1/3 to 1/2 atmospheric pressure microwave plasma assisted chemical vapor deposition reactors
Authors: Jes Asmussen
Affiliation: Michigan State University
Title: The Jahn-Teller Distortion at High Pressure: Case of Copper Difluoride
Authors: Dominik Kurzydłowski
Affiliation: Centre of New Technologies, University of Warsaw, Warsaw 02-097 , Poland; Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszyński University, Warsaw 01-038 , Poland;
Abstract: The opposing effects of high pressure (in the GPa range) and the Jahn-Teller distortion lead to many intriguing phenomena which are still not well understood. Here we report a combined experimental-theoretical study on an archetypical Jahn-Teller system, copper difluoride (CuF2). At ambient conditions this compound adopts a distorted rutile structure of P21/c symmetry. Raman scattering measurements performed up to 30 GPa indicate that CuF2 undergoes a phase transition at 9 GPa. By comparing experimental Raman frequencies with those obtained by Density Functional Theory (DFT) calculations we assign the novel high-pressure phase to a distorted fluorite structure of Pbca symmetry. Moreover we predict that the Pbca structure should transform to a non centrosymmetric Pca21 polymorph above 35 GPa, which in turn should be replaced by a cotunnite-like phase (Pnma symmetry) at 72 GPa. Interestingly we find that the 2D character found in the ambient pressure structure of CuF2 is retained in the Pbca and Pca21 high-pressure polymorphs, while the Pnma structure stable at the highest pressures is built of 1D chains. Our results, which indicate that the strong Jahn-Teller effect found for CuF2 is not suppressed even at 100 GPa, are put into the context of previous high-pressure investigations of Jahn-Teller systems, in particular bearing Cu2+ and Ag2+ cations.
Title: Correlations Between Crystal and Electronic Structures in the Jahn-Teller Insulating Ferromagnet CsMnF4 Under Pressure
Authors: Fernando Aguado1; Michael Hanfland2 and Fernando Rodriguez1,*
Affiliation: MALTA Consolider Team, DCITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander, Spain; ESRF, BP220, 156 rue des Martires, 38043 Grenoble Cedex, France; Email: firstname.lastname@example.org
Abstract: Structural studies of Jahn-Teller (JT) systems involving transition metal ions often require using complementary spectroscopic techniques beyond x-ray diffraction to achieve a suitable characterization. Here we present a structural study of the insulating ferromagnet CsMnF4 with pressure. This compound exhibits an ideal layer perovskite structure, in which the JT distorted MnF6 octahedra shows an in-plane antiferrodistortive layer structure, in which the long axial F- anion of one Mn3+ acts as the short equatorial inplane ligand of the in-plane neighbouring Mn3+ cations. This configuration is responsible for the ferromagnetic interaction between Mn3+ ions yielding 3D ferromagnetism below Tc = 15.9 K. Replacing Cs for Na the crystal structure transforms from tetragonal (Cs) to monoclinic (Na) making NaMnF4 antiferromagnetic with MnF6 octahedra exhibiting a significant out-of-layer tilting. This work shows that pressure induces a progressive reduction of long in-plane Mn-F distance yielding reduction of the JT distortion up to 1.8 GPa. Above this pressure, CsMnF4 experiences a P4/n ->P21/a second-order structural phase transition associated with out-of-plane tilts of the MnF6 octahedra. This transition breaks out the ideal layer perovskite structure towards a lower-symmetry monoclinic structure as a way to preserve the highly stable JT distortion of MnF6 against lattice compression. Such structural transformations induce changes of the Mn3+ electronic structure that can be detected by optical spectroscopy. Correlations between crystal and structure and electronic Mn3+ energy levels allow us exploring the stability of the JT distortion in an ample pressure range up to 35 GPa and obtaining the main electron-lattice coupling parameters of interest in predicting structural distortion in JT systems.