GeTe(1-x)-Sb2Te3(x) sputtered amorphous film was crystallized into a simple NaCl-type structure through instantaneous laser irradiation over a wide composition range from x = 0 to at least 2/3. When the ratio of Sb2Te3 increases, a vacancy is generated at every Na site for two Sb atoms. The fraction of vacancies, v(x), changes according to x/(1 + 2x), and the cubic root unit cell volume varies with a strong correlation to v(x). Through these created vacancies, valence electrons provided by adjacent Ge/Sb and Te atoms remain constant regardless of the composition, ensuring that these electrons occupy predominantly the bonding molecular orbitals. This results in crystal chemical stability, with the closed shell p-p bondings in the valence electrons arranging the crystal's atomic configuration into an NaCl-type structure.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ic051677w | DOI Listing |
Phys Chem Chem Phys
November 2024
Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Science, Novosibirsk 630090, Russian Federation.
Based on density functional theory and evolutionary algorithms the thermodynamically stable structures of MnN and their stability - fields were revealed in the pressure range of 0-50 GPa. The MnN-4̄3 polymorph (zinc blende-type) was shown to be the ambient pressure phase, while experimentally known MnN-4/ (distorted NaCl-type) is a high-temperature phase quenchable to the ambient condition. At 5.
View Article and Find Full Text PDFSci Bull (Beijing)
October 2024
College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), and Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies, Soochow University, Suzhou 215006, China; Shanghai Qi Zhi Institute, Shanghai 200232, China. Electronic address:
We present a full space inverse materials design (FSIMD) approach that fully automates the materials design for target physical properties without the need to provide the atomic composition, chemical stoichiometry, and crystal structure in advance. Here, we used density functional theory reference data to train a universal machine learning potential (UPot) and transfer learning to train a universal bulk modulus model (UBmod). Both UPot and UBmod were able to cover materials systems composed of any element among 42 elements.
View Article and Find Full Text PDFACS Mater Au
July 2024
Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
High-pressure synthesis in the diamond anvil cell suffers from the lack of a general approach for the control of precursor stoichiometry and homogeneity. Here, we present results from a new method we have developed that uses magnetron cosputtering to prepare stoichiometrically precise and atomically mixed amorphous films of Cr:C. Laser-heated diamond anvil cell experiments carried out on a flake of this sample at pressures between 13.
View Article and Find Full Text PDFNanomaterials (Basel)
June 2024
Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, 25, J. Bottu St., 917 24 Trnava, Slovakia.
This study investigates the phase composition, microstructure, and their influence on the properties of Mo-W-C nanocomposite films deposited by dual-source magnetron sputtering. The synthesised films consist of metal carbide nanograins embedded in an amorphous carbon matrix. It has been found that nanograins are composed of the hexagonal β-(Mo + W)C phase at a low carbon source power.
View Article and Find Full Text PDFChem Commun (Camb)
June 2024
MDX Research Center for Element Strategy, International Research Frontiers Initiative, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!