铋钼单晶的制备和输运性质的研究

The Growth of Single Crystal of Bismuth Molybdenum Oxide and Its Electric Transport

以高纯度的Ｂｉ２Ｏ３和ＭｏＯ３为原料，采用电化学方法制备了高质量紫红色Ｂｉ－Ｍｏ－Ｏ单晶，并研究了其输运性质．发现Ｂｉ－Ｍｏ－Ｏ单晶为半导体材料，其电阻随温度的变化可用公式Ｒ＝Ｒ０ｅｘｐ［Ｅａ／（２ｋＢＴ）］来描述；Ｉ－Ｖ特性的测量表明，Ｂｉ－Ｍｏ－Ｏ单晶中存在着一个阈值场，当外场低于阈值场时，材料呈现欧姆特性，高于阈值场时，单晶呈现出很强的非线性特征．

By making use of the electrolytic reduction of the molten salt of Bi2O3-MoO3, single crystal of bismuth molybdenum oxide was successfully grown with large side and high quality. The electrical resistance is measured over the temperature range 120-300 K. The sample performs semiconducting behavior, fitting the expression R=R0exp[Ea/(2kBT)] quite well and the thermal activation energy Ea being nearly equal to 0.30 eV. The I-V characteristic measurement was also carried out in room tem- perature. The results show that there exist a threshold field (VT). If V is below the field, the I-V characteristic is linear. Drastic nonlinear phenomena were observed when V is over the threshold field.