高温高压下β相硼的电导率测量  

Electrical Conductivity Measurement of β-Boron under High Temperature and High Pressure

作　　者：张东梅[1] 高春晓[1] 黄晓伟[1] 李明[1] 贺春元[1] 郝爱民[1] 于翠玲[1] 崔晓岩[1] 李延春[2] 

机构地区：[1]吉林大学超硬材料国家重点实验室,吉林长春130012 [2]中国科学院高能物理研究所,北京100039

出　　处：《高压物理学报》2008年第1期25-29,共5页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(40473034,40404007,10574055,50532020);973计划资助课题(2005CB724404)

摘　　要：硼在高压下具有复杂的结构和多样的物理性质，对其结构和性质的深入研究具有很重要的意义，一直引起理论和实验研究领域的关注。高压下进行电学性质测量是获得物质物理性质的有效手段，利用集成在金刚石对顶砧上的微电路，在高压下和两个不同温度范围内对β相硼进行了电导率测量，分析了导电机制随压力的变化规律。在0～28．1GPa范围内，β相硼的电导率随着压力的增大是逐渐增大的，卸压后样品的电导率不能回到最初的状态，是一个不可逆的变化过程；由室温到423K的范围内，β硼的电导率随着温度的不断增加有明显的上升趋势，并且随着压力的升高，电导率变化逐渐加快。此外，对样品在14．5GPa和18．6GPa压力下，用溅射到金刚石对顶砧上的氧化铝薄膜做绝热层，对样品进行了激光加热实验，最高温度达到2224K，电导率随着温度的上升而增大，结果显示，β相硼的电学特征仍然属于半导体的特征范围内。Boron possesses very complex structures and various physical characteristics under high pressure,which always attracts much attention in the field of theory and experiment. In-situ electrical conductivity measurement under variable pressure and temperature conditions is a very important research into exploring conductive property of substance. Electrical conductivity of β-B was measured with metallic microcircuit fabricated on the diamond anvil cell（DAC）, and the conductive physical mechanism of β-boron at high pressure and high temperature was analyzed. When sample was not heated, electrical conductivity of boron was rising with increasing pressure to 28 GPa;furthermore,we found that it almost recovers original state upon decompression. When temperature is changed from room temperature to 423 K, electrical conductivity begins to rise with increasing temperature, and the change rate becomes gradually high and the change trend of electrical conductivity is similar to that under different pressures in the same temperature range. Subsequently, laser-heating was performed on β-B with designed DAC,Al2O3 thin film was deposited on the diamond anvil and used as heat resistant and electrical insulating layer. Electrical conductivity was separately measured at 14.5 GPa and 18.6 GPa. The highest temperature reached is 2 224 K. β-boron is confirmed semiconductor property based on electrical conductivity increasing with elevated temperature.

关 键 词：高温高压 β相硼 电导率 

分 类 号：O521.2[理学—高压高温物理]