Low-Temperature Heat Capacity and Defect Structure of Yttria Stabilized Zirconia.

Low-temperature heat capacity of pure zirconia and yttria stabilized zirconia (YSZ) was measured by adiabatic calorimetry. YSZ showed excess heat capacity compared with pure zirconia. The excess heat capacity, which should be attributed to the stabilization of cubic structure caused by yttria doping of several mol %, decreases with increasing yttria content. The vibrational property and defect structure are discussed in detail. The molecular dynamics simulation performed on the YSZ showed that the lattice relaxation around oxygen vacancy played an important role in vibrational property of YSZ.