Special Issue "Carbon-Refractory Metals Nanostructures: Synthesis, Characterization and Applications"

A special issue of Materials (ISSN 1996-1944).

Deadline for manuscript submissions: 30 June 2020.

Special Issue Editor

Prof. Dr. Rodica Vlǎdoiu
Website
Guest Editor
Department of Physics and Electronics, Faculty of Applied Science and Engineering, Ovidius University of Constanta, Mamaia Av. no 124, Constanta, 900524, Romania
Interests: thin films coatings; materials characterization; vacuum arc deposition technologies for nanostructures
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

There is a great demand for joining carbon with other elements, which ensures high resistance against chemical and corrosive environment attacks, as well as, importantly, the better adherence of the carbon to the coated substrates.

This Special Issue is focused on the emerging concepts allowing the design of new or improved carbon-refractory metals with improved nanostructured performance, as well as the characterization of the microstructure and properties of carbon-based materials with high resistance to heat and wear. 

The main goal is to present the latest developments in the field of carbon-refractory metal nanostructures to enhance their specific functionality in industrial applications. This Special Issue will be an overview of the characterization and applications of the nanostructured complex combination of carbon with refractory metals (niobium, molybdenum, tantalum, tungsten and rhenium, but also considering all elements with a melting point above 2,123 K) using different methods for synthesis. The topics of interest include, but are not limited to:

  • Innovative synthesis and characterization methodologies
  • New technology trends and applications
  • Surfaces, interfaces and thin films
  • Substrate influence, sample preparation
  • Experimental condensed matter physics

Prof. Dr. Rodica Vlǎdoiu
Guest Editor

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. Materials is an international peer-reviewed open access semimonthly 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 2000 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.

Keywords

  • carbon
  • refractory metals
  • synthesis
  • characterization

Published Papers (4 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Detailed Molecular and Structural Analysis of Dual Emitter IrQ(ppy)2 Complex
Materials 2020, 13(7), 1617; https://doi.org/10.3390/ma13071617 - 01 Apr 2020
Abstract
The molecular structure of the 8-hydroxyquinoline–bis (2-phenylpyridyl) iridium (IrQ(ppy)2) dual emitter organometallic compound is determined based on detailed 1D and 2D nuclear magnetic resonance (NMR), to identify metal-ligands coordination, isomerization and chemical yield of the desired compound. Meanwhile, the extended X-ray [...] Read more.
The molecular structure of the 8-hydroxyquinoline–bis (2-phenylpyridyl) iridium (IrQ(ppy)2) dual emitter organometallic compound is determined based on detailed 1D and 2D nuclear magnetic resonance (NMR), to identify metal-ligands coordination, isomerization and chemical yield of the desired compound. Meanwhile, the extended X-ray absorption fine structure (EXAFS) was used to determine the interatomic distances around the iridium ion. From the NMR results, this compound IrQ(ppy)2 exhibits a trans isomerization with a distribution of coordinated N-atoms in a similar way to facial Ir(ppy)3. The EXAFS measurements confirm the structural model of the IrQ(ppy)2 compound where the oxygen atoms from the quinoline ligands induce the splitting of the next-nearest neighboring C in the second shell of the Ir3+ ions. The high-performance liquid chromatography (HPLC), as a part of the detailed molecular analysis, confirms the purity of the desired IrQ(ppy)2 organometallic compound as being more than 95%, together with the progress of the chemical reactions towards the final compound. The theoretical model of the IrQ(ppy)2, concerning the expected bond lengths, is compared with the structural model from the EXAFS and XRD measurements. Full article
Show Figures

Graphical abstract

Open AccessArticle
Synthesis and Characterization of Complex Nanostructured Thin Films Based on Titanium for Industrial Applications
Materials 2020, 13(2), 399; https://doi.org/10.3390/ma13020399 - 15 Jan 2020
Cited by 1
Abstract
Titanium-based composites—titanium and silver (TiAg) and titanium and carbon (TiC)—were synthesized by the Thermionic Vacuum Arc (TVA) method on substrates especially for gear wheels and camshaft coating as mechanical components of irrigation pumps. The films were characterized by surface morphology, microstructure, and roughness [...] Read more.
Titanium-based composites—titanium and silver (TiAg) and titanium and carbon (TiC)—were synthesized by the Thermionic Vacuum Arc (TVA) method on substrates especially for gear wheels and camshaft coating as mechanical components of irrigation pumps. The films were characterized by surface morphology, microstructure, and roughness through X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Small-Angle Neutron Scattering (SANS). The silver (Ag) films crystallized into a cubic system with lattice a = 4.0833 Å at room temperature, indexed as cubic Ag group Fm3m. The crystallites were oriented in the [111] direction, and mean grain size was <D>111 = 265 Å. The TiC structure revealed a predominant cubic TiC phase, with a = 0.4098 as a lattice parameter determined by Cohen’s method. Average roughness (Ra) was 8 nm for the as-grown 170 nm thick TiAg film, and 1.8 nm for the as-grown 120 nm thick TiC film. Characteristic SANS contribution was detected from the TiAg layer deposited on a substrate of high-quality stainless steel with 0.45% carbon (OLC45) in the range of 0.015 Å−1 ≤ Q ≤ 0.4 Å−1, revealing the presence of sharp surfaces and an averaged triaxial ellipsoidal core-shell object. Full article
Show Figures

Figure 1

Open AccessArticle
Structural, Compositional, and Mechanical Characterization of WxCryFe1−x−y Layers Relevant to Nuclear Fusion, Obtained with TVA Technology
Materials 2019, 12(24), 4072; https://doi.org/10.3390/ma12244072 - 06 Dec 2019
Abstract
Reduced activation ferritic and martensitic steel like EUROFER (9Cr-1W) are considered as potential structural materials for the first wall of the future next-generation DEMOnstration Power Station (DEMO) fusion reactor and as a reference material for the International Thermonuclear Experimental Reactor (ITER) test blanket [...] Read more.
Reduced activation ferritic and martensitic steel like EUROFER (9Cr-1W) are considered as potential structural materials for the first wall of the future next-generation DEMOnstration Power Station (DEMO) fusion reactor and as a reference material for the International Thermonuclear Experimental Reactor (ITER) test blanket module. The primary motivation of this work is to study the re-deposition of the main constituent materials of EUROFER, namely tungsten (W), iron (Fe), and chromium (Cr), in a DEMO type reactor by producing and analyzing complex WxCryFe1−x−y layers. The composite layers were produced in laboratory using the thermionic vacuum arc (TVA) method, and the morphology, crystalline structure, elemental composition, and mechanical properties were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-X-ray fluorescence (micro-XRF), and glow discharge optical emission spectrometry (GDOES), as well as nanoindentation and tribology measurements. The results show that the layer morphology is textured and is highly dependent on sample positioning during the deposition process. The formation of polycrystalline WxCryFe1−x−y was observed for all samples with the exception of the sample positioned closer to Fe anode during deposition. The crystalline grain size dimension varied between 10 and 20 nm. The composition and thickness of the layers were strongly influenced by the in-situ coating position, and the elemental depth profiles show a non-uniform distribution of Fe and Cr in the layers. The highest hardness was measured for the sample positioned near the Cr anode, 6.84 GPa, and the lowest was 4.84 GPa, measured for the sample positioned near the W anode. The tribology measurements showed an abrasive sliding wear behavior for most of the samples with a reduction of the friction coefficient with the increase of the normal load. Full article
Show Figures

Figure 1

Open AccessArticle
Hydration Resistance of CaO Material Prepared by Ca(OH)2 Calcination with Chelating Compound
Materials 2019, 12(14), 2325; https://doi.org/10.3390/ma12142325 - 22 Jul 2019
Cited by 1
Abstract
The hydration resistance of CaO materials prepared by Ca(OH)2 calcination with chelating compounds are investigated in this paper. The crystalline phases and microstructure characteristics of sintered specimens were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and energy [...] Read more.
The hydration resistance of CaO materials prepared by Ca(OH)2 calcination with chelating compounds are investigated in this paper. The crystalline phases and microstructure characteristics of sintered specimens were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and energy dispersive spectrometer (SEM, EDS). The bulk density, apparent porosity, and hydration resistance of samples were also tested. The results showed that chelating compounds improved the hydration resistance of the treated CaO specimens significantly. The surface-pretreated specimens showed an increase in bulk density and a decrease in apparent porosity after heating. The surface pretreatment of the Ti chelating compound promoted the solid phase sintering and grain growth of CaO specimens, which increased the density of the heated CaO sample. The Al chelating compound promoted the liquid-phase sintering of CaO specimens, which led to the grain growth and increased density of the sample. CaO grains were bonded by the formed tricalcium aluminate (C3A) and the apparent porosity of the sample was reduced, reducing the contact area of CaO with water vapor. The Al chelating compound was more effective in improving the hydration resistance of the CaO material in the situation of this study. Full article
Show Figures

Figure 1

Back to TopTop