Investigation of chemical bond characteristics, thermal expansion coefficients and bulk moduli of α-R2MoO6 and R2Mo2O7 (R = rare earths) by using a dielectric chemical bond method
✍ Scribed by Huaiyong Li; Siyuan Zhang; Shihong Zhou; Xueqiang Cao
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 258 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Theoretical researches are performed on the α‐R~2~MoO~6~ (R = Y, Gd, Tb Dy, Ho, Er, Tm and Yb) and pyrochlore‐type R~2~Mo~2~O~7~ (R = Y, Nd, Sm, Gd, Tb and Dy) rare earth molybdates by using chemical bond theory of dielectric description. The chemical bonding characteristics and their relationship with thermal expansion property and compressibility are explored. The calculated values of linear thermal expansion coefficient (LTEC) and bulk modulus agree well with the available experimental values. The calculations reveal that the LTECs and the bulk moduli do have linear relationship with the ionic radii of the lanthanides: the LTEC decreases from 6.80 to 6.62 10^−6^/K and the bulk modulus increases from 141 to 154 GPa when R goes in the order Gd, Tb Dy, Ho, Er, Tm, and Yb in the α‐R~2~MoO~6~ series; while in the R~2~Mo~2~O~7~ series, the LTEC ranges from 6.80 to 6.61 10^−6^/K and the bulk modulus ranges from 147 to 163 GPa when R varies in the order Nd, Sm, Gd, Tb and Dy. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009