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Theoretical Investigations on the Structural, Electronic, Mechanical, and Thermal Properties of MP 2 O 7 ( M = Ti , Hf )
Author(s) -
Xiang Huimin,
Feng Zhihai,
Zhou Yanchun
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12961
Subject(s) - bulk modulus , chemistry , thermal , lattice constant , materials science , crystallography , thermodynamics , composite material , physics , diffraction , optics
A systematical ab initio analysis on MP 2 O 7 (M = Ti, Hf) is presented in this work. Density functional theory ( DFT ) computations were performed for the electronic, mechanical, and thermal properties of MP 2 O 7 . Heterogeneous bonding nature of MP 2 O 7 was revealed by examining the structural and electronic properties, M–O bonds were weaker than P–O bonds. The elastic constants and polycrystalline mechanical properties of MP 2 O 7 were reported. Based on the low shear‐modulus‐to‐bulk‐modulus ratios and positive Cauchy pressure, MP 2 O 7 ceramics were predicted to be “quasi‐ductile”. In addition, the minimum thermal conductivities were estimated to be 1.52 and 0.99 W·m −1 ·K −1 for TiP 2 O 7 and HfP 2 O 7 , respectively. The ultra‐low thermal conductivities were contributed to the lattice phonon scattering due to the heterogeneous bonding nature. Our theoretical results emphasize the importance of weak M–O bonds in the determination of mechanical and thermal properties of MP 2 O 7 .