机构地区: 中山大学物理科学与工程技术学院物理系
出 处: 《无机材料学报》 1990年第3期193-199,共7页
摘 要: 提出了一个可靠的方法排除热释电讯号的干扰,利用同一个样品将高绝缘铁电单晶的表面电阻和体电阻分开来测量。在70~170℃温度范围内,对不同切向的纯铌酸锂单畴和多畴单晶的表面电阻和体电阻进行了详细的测量。实验数据支持表面和体内都具有跳跃导电机构,给出了不同方向跳跃导电激活能在0.895~1.096eV之间。 A method is suggested for finding the correct conduction current from the pyroelectric interference signals of a high insulation ferroelectric crystal.In thetemperature region of 70 to 170℃,the surface and body conductivities of purelithium niobate polarized and unpolarized single crystals are measured carefully forvarious directions.All the results show a hopping conduction mechanism either inthe bulk or on the surface of the crystals.The activation energies are lying from0.895 to 1.096eV.The experiments support that the screening charge of the spont-aneous polarization of the ferroelectric crystal is surface polarons.The mobilitiesand densities of the carriers in various situations are given.