2006 年 48 巻 1 号 p. 36-41
Thermodynamic studies of disordered sructure by heat capacity measurements are reviewed, and the important role of thermodynamic properties is explained. The heat capacity anomaly and the excess entropy due to the formation of short-range order in relaxor ferroelectrics are discussed. The excess heat capacity at low temperatures is analyzed on the basis of the disorder structures for glasses and disordered crystals. The lattice vibration spectrum in stabilized zirconia is discussed in terms of disorder in the crystal.