Journal ArticleDOI
Synthesis of cubic zirconium and hafnium nitride having Th3P4 structure.
TLDR
The high-pressure synthesis of zirconium and hafnium nitrides with the stoichiometry M3N4, where M = Zr, Hf, are reported, which may be the first members of a larger group of transition metal and/or lanthanides with interesting ferromagnetic or superconducting behaviour.Abstract:
High-pressure synthesis is a powerful method for the preparation of novel materials with high elastic moduli and hardness. Additionally, such materials may exhibit interesting thermal, optoelectronic, semiconductuing, magnetic or superconducting properties. Here, we report on the high-pressure synthesis of zirconium and hafnium nitrides with the stoichiometry M3N4, where M = Zr, Hf. Synthesis experiments were performed in a laser-heated diamond anvil cell at pressures up to 18 GPa and temperatures up to 3,000 K. We observed formation of cubic Zr3N4 and Hf3N4 (c-M3N4) with a Th3P4-structure, where M-cations are eightfold coordinated by N anions. The c-M3N4 phases are the first binary nitrides with such a high coordination number. Both compounds exhibit high bulk moduli around 250 GPa, which indicates high hardness. Moreover, the new nitrides, c-Zr3N4 and c-Hf3N4, may be the first members of a larger group of transition metal and/or lanthanide nitrides with interesting ferromagnetic or superconducting behaviour.read more
Citations
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Journal ArticleDOI
Crystal structures and elastic properties of superhard IrN2 and IrN3 from first principles
TL;DR: In this paper, first principles calculations were performed to investigate the structural, elastic, and electronic properties of IrN2 for various space groups: cubic Fm-3m and Pa-3, hexagonal P3(2)21, tetragonal P4(2)/mnm, orthorhombic Pmmn, Pnnm, and Pnn2, and monoclinic P2(1)/c.
Journal ArticleDOI
Microscopic theory of hardness and design of novel superhard crystals
Yongjun Tian,Bo Xu,Zhisheng Zhao +2 more
TL;DR: In this article, the authors present three most popular microscopic models based on distinct scaling schemes of this resistance, namely the bond resistance, bond strength, and electronegativity models, with key points during employing these microscopic models addressed.
Journal ArticleDOI
Synthesis and characterization of a binary noble metal nitride
Eugene Gregoryanz,Chrystele Sanloup,Maddury Somayazulu,James Badro,Guillaume Fiquet,Ho-kwang Mao,Russell J. Hemley +6 more
TL;DR: The discovery and characterization of platinum nitride (PtN), the first binary nitride of the noble metals group, is reported, characterized by a very high Raman-scattering cross-section with easily observed second- and third-order Raman bands.
Journal ArticleDOI
Synthesis and Characterization of the Nitrides of Platinum and Iridium
Jonathan C. Crowhurst,Jonathan C. Crowhurst,Alexander F. Goncharov,Alexander F. Goncharov,Babak Sadigh,Babak Sadigh,Cheryl L. Evans,Cheryl L. Evans,Peter G. Morrall,Peter G. Morrall,James Ferreira,James Ferreira,Art J. Nelson,Art J. Nelson +13 more
TL;DR: A recently synthesized platinum nitride (PtN) that was shown to have a large bulk modulus is evaluated, and a structure that is isostructural with pyrite and has the stoichiometry PtN2 is proposed.
Journal ArticleDOI
Tungsten tetraboride, an inexpensive superhard material
Reza Mohammadi,Andrew T. Lech,Miao Xie,Beth E. Weaver,Michael T. Yeung,Sarah H. Tolbert,Richard B. Kaner +6 more
TL;DR: Powders of tungsten tetraboride with and without 1 at.% Re addition are thermally stable up to approximately 400 °C in air as measured by thermal gravimetric analysis.
References
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PatentDOI
Low compressibility carbon nitrides
David M. Teter,Russell J. Hemley +1 more
TL;DR: A cubic form of C3N4 with a zero-pressure bulk modulus exceeding that of diamond is described in this paper, and a process for preparing such product which comprises combining carbon and nitrogen at a pressure of 120,000 to 800,000 atmosphere and a temperature of 1000-3000 °C is described.
Book
Handbook on the Physics and Chemistry of the Actinides
A.J. Freeman,C. Keller +1 more
TL;DR: The second volume of the Handbook of actinides as discussed by the authors is devoted to the more chemical, physico-chemical, structural, and environmental aspects of the actinide elements.
Book
Phase Diagrams of the Elements
TL;DR: In this article, a summary of the pressure-temperature phase diagrams of the elements is presented, with graphs of the experimentally determined solid-solid phase boundaries and melting curves.
Journal ArticleDOI
Synthesis of cubic silicon nitride
Andreas Zerr,Gerhard Miehe,George Serghiou,Marcus Schwarz,Edwin Kroke,Ralf Riedel,Hartmut Fueß,Peter Kroll,Reinhard Boehler +8 more
TL;DR: The hardness of the new phase, c-Si3N4, is comparable to that of the hardest known oxide (stishovite3, a high-pressure phase of SiO2), and significantly greater than the hardness of two hexagonal polymorphs as mentioned in this paper.
BookDOI
Handbook of ceramic hard materials.
TL;DR: In this article, the authors present a structural and physicochemical analysis of ultrahard materials, including carbon and carbonitrides, based on the CO 2 -Laser Heating Technique in a diamond cell.