一种新的恶二唑衍生物在金刚石对顶砧中的电阻率随压力和温度的变化关系

利用金刚石对顶砧测量了恶二唑衍生物微晶, 1,4-bis[(4-methyloxyphenyl)-1,3,4-oxadiazolyl]- 2,5-bisheptyloxyphenylene (OXD-2), 电阻随压力和温度的变化关系，并利用有限元分析方法计算了样品的电阻率。实验中，测量压力和温度达到了16 GPa和150℃。样品的电阻率随着温度的升高而降低，说明样品表现出半导体传导特性。在90-100 ℃之间，样品的电阻率有一明显的下降，说明这时发生了温度诱导的相变。随着压力的增加，样品的电阻率在6GPa左右达到最大值，此后随着压力的增加而下降。结合原位x光数据，在6GPa左右的电阻突变应该是由于样品在压力的诱导下发生了无序化的相变。

Electrical resistivity of a novel oxadiazole derivative as a function of pressure and temperature using a diamond anvil cell

The in-situ electrical resistance measurement on the microcrystal of 1,4-bis[(4-methyloxyphenyl)-1,3,4-oxadiazolyl]- 2,5-bisheptyloxyphenylene (OXD-2) has been carried out under conditions of high pressure and temperatures higher than room temperature by using the diamond anvil cell (DAC). Sample’s resistivity was calculated with a finite element analysis method. The temperature and pressure dependencies of the resistivity of OXD-2 microcrystal were measured up to 150 oC and 16 GPa. The resistivity of OXD-2 decreases with increasing temperature, indicating that OXD-2 exhibits organic-semiconductor conducting property in the region of experimental pressure. Between 90-100 ℃, the resistivity drops with the temperature, which reveals a temperature-induced phase transition. As the pressure increases, the resistivity of OXD-2 increases and reaches a maxium at about 6 GPa, and then begins to decrease at higher pressures. Combining the in-situ x-ray diffraction data with the resistivity measurement results under pressure, the anomaly resistivity drop after 6 GPa is confirmed to be from the pressure-induced amorphous phase transition of OXD-2.