ISSN:
1432-2021
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Abstract The single crystal elastic moduli bear evidence of non-central or many-body forces in the simple oxides with transition-metal oxides being very distinctive from alkaline-earth oxides. These features which persist in more complicated structures such as olivine, suggest that noncentral or many-body forces are important in defining the physical properties of these compounds as well. Within the framework of a Born type static lattice model, the elastic properties of simple oxides can be described with charges which are less than the formal charge, anioncation repulsive forces, and angle-bending forces. The transition-metal oxides and alkaline-earth oxides mainly differ in the nature of the angle-bending forces, where even the sign could be different. The potentials which are derived to fit the simple oxide properties, serve very well to define the crystal structure and elastic properties of Mn, Mg, and Co silicate olivines. In the case of Mg, the predicted crystal structure and elastic properties were better predicted than a model without the angle-bending forces and one where the other potential terms were derived as to optimize the fit of the structure. In all cases, the relationship of the off-diagonal and shear moduli are well modeled by including the angle-bending forces.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00201328
