We measured the temperature dependences of light reflection and transmission of bismuth germanate single crystals upon cyclic variation of their temperature in the range of 94-340 K. We revealed an asymmetric temperature hysteresis of reflection, which is accompanied by a change in the Rayleigh scattering. Heating of crystals, in contrast to their cooling, is accompanied by a decrease in the reflection in the range of 100-287 K and near 310 K. We found that reflection minima in the first and second temperature ranges arise as a result of the action of different mechanisms. We assume that temperature changes in the reflection are related to structural phase transitions in the superficial layer.
展开▼
