First-principles calculation and anharmonic dynamical theory were used in sequence to explain a large excess heat capacity observed in yttria-stabilized zirconia in comparison with the additive rule value. It is found that the excessive shape of heat capacity decays gradually with the Y$_{ 2}$O$_{ 3}$ doping when the number of environmentally different O sites falls to its zero value at 33 mol % Y$_{ 2}$O$_{ 3}$-ZrO$_2$ due to the Y atoms adjacent. The model and results presented in this work provide a key insight into the complex behaviour and characterization of fast-ion conductors.
Categories: cond-mat.mtrl-sci cond-mat.dis-nn