Optical Behaviours of Multi-domain Single Crystal of BaTiO₃ in Dependence on Temperature

抄録

Apparent absorption edge, transmissivity and true characteristic absorption edge of multi-domain single crystal of barium titanate have been measured in dependence on temperature covering the three transition points, −70°C, 5°C and 120°C. The true characteristic absorption edge shifts linearly with the temperature coefficient quite close to that in ionic crystals which has so far been well known. Both the apparent absorption edge and the transmissivity exhibit quite steep hysteresis curves especially near −70°C. It may be due to the domain structure which is expected to develope when the lattice changes from orthorhombic to rhombohedral near this transition point.