Effects of Temperature and Pressure on a Novel 1,3,4-Oxadiazole Derivative

The electrical resistivity variation of 1,4-bis[(4-methylphenyl)-1,3,4-oxadiazolyl]phenylene (OXD-1) microcrystal is studied under variable pressure and temperature conditions by a quasi four-probe method in a diamond anvil cell. The sample resistivity is calculated with a finite element analysis method. The temperature and pressure dependencies of resistivity of OXD-1 microcrystal are measured up to 150 degrees C and 15 GPa. The resistivity decrease with temperature increasing indicates that OXD-1 exhibits an organic-semiconductor transport property in the experimental pressure region. With pressure increasing, the resistivity of OXD-1 increases firstly and reaches the maximum at about 6.2 GPa, and then begins to decrease as the pressure increases continuously. In situ x-ray diffraction data under pressure provide obvious prove that the anomaly of resistivity variation at 6.2 GPa is caused by the pressure-induced amorphism of OXD-1.