CaMoO-=SUB=-4-=/SUB=--NaGd(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=- Solid Solutions: simulation of properties and local structure by the method of interatomic potentials

Abstract

Simulation of CaMoO4-NaGd(MoO4)2 solid solutions by the method of interatomic potentials is carried out. It is shown that solid solutions exist in the entire range of compositions and are close to ideal. Dependences on the composition of the lattice parameters and volume of the unit cell, density, bulk modulus, enthalpy, vibrational entropy and heat capacity are obtained. Temperature dependences of heat capacity and vibrational entropy are constructed. Analysis of the local structure and its changes depending on the composition of the Ca1-xNax/2Gdx/2MoO4 solid solution showed that in solid solution the interatomic distances of Gd-O are on average 2.62% less, and Na-O is 3.15% greater than the distances of Ca-O. In general, this leads to an increase in the lattice parameters and volume of the unit cell during the formation of Ca1-xNax/2Gdx/2MoO4 solid solutions compared to CaMoO4. Keywords: simulation, molybdates, the solid solutions, local structure.