Investigation of mechanical and thermal properties of rare earth pyrochlore oxides by first‐principles calculations

Abstract

Abstract The pyrochlore‐type rare‐earth oxides attract considerable attentions due to their outstanding properties and extensive applications. In this work, contour maps of mechanical/thermal properties as a function of A and B cation radii across a wide variety of A 2 B 2 O 7 ( A = La‐Lu and Y; B = Ti, Sn, Hf, Zr, Pr and Ce) pyrochlore oxides are studied using the first‐principles calculations. The mechanical/thermal properties vary dramatically with increasing of the B cation sizes but do not show a strong systematic dependence on the A cation sizes. Furthermore, the machine learning algorithm is performed for the large family of pyrochlores and the parameters playing key role on mechanical/thermal properties are clarified. Besides, the expressions of focused mechanical and thermal properties are constructed. These results are expected to guide the future material design through composition tailoring.