Crystal structure analysis under uniaxial strain at low temperature using a unique design of four-axis x-ray diffractometer with a fixed sample

For the purpose of crystal structure analysis under uniaxial strain at low temperatures, we developed a pressure cell for uniaxial compression and a unique design of an x-ray diffractometer wherein both the x-ray source and the detector are capable of two-axial rotation with a fixed sample. This arrangement is advantageous to crystal structure analyses under extreme conditions that require a large and heavy apparatus. Using the present diffractometer, we performed the crystal structure analyses of the organic conductor, α-(BEDT–TTF)2I3 (BEDT–TTF denotes bis(ethylene)dithio-tetrathiafulvalene), under uniaxial strain and ambient pressure, and at room and low temperatures, and obtained results that were qualitatively consistent with those of resistivity measurements.