Semi-Empirical Predictions for Hardness of Rare Earth Pyrochlores; High-Permittivity Dielectrics and Thermal Barrier Coating Materials

Abstract

Herein, we have formulated a simplistic semi-empirical model for Vicker’s hardness of rare earth based pyrochlore compounds. We have considered the structured 97 pyrochlore compounds for Vicker’s hardness calculations. The plasmon energy (ħωp) depends on basic parameters of the material such as Ne-effective number of free electrons per unit volume participating in plasma oscillations, e-electronic charge and m-mass of an electron. The proposed model predicts that the experimental and theoretical values of Vicker’s hardness increases as plasmon energy of pyrochlore increases. We have found that the calculated values are in better agreement with available experimental and theoretical data, which supports the validity of the model. This model supports the modeling of emerging functional pyrochlore compounds and helps to understand their mechanical properties for excellent thermal stability, superconductivities, batteries, ferroelectricity, water spitting, high ionic conductivity, good photoluminescence, inherent oxygen vacancies, exotic magnetism, and now-a-days most importantly in nuclear waste encapsulation and aerospace industry

Keywords

• pyrochlores
• plasmon energy
• vicker’s hardness