The [Formula: see text] sample with the nominal composition was synthesized. Powder X-ray diffraction (XRD) experiments confirm that it crystallizes in an orthorhombic structure with space group Immm. The synchrotron powder XRD results suggest that the crystal structure of [Formula: see text] keeps stable under pressure up to 34 GPa at room temperature with nearly isotropic compressibility. The equation of state for [Formula: see text] was obtained. The results offer opportunities to further synthesize and research [Formula: see text] superconductor with tetragonal [Formula: see text] structure.

The bulk Ca 2 CrO 4 samples were synthesized under high pressure and high temperature conditions using CaO and CrO 2 as starting materials. The structure of the prepared Ca 2 CrO 4 solid is characterized by X-ray diffraction with Rietveld refinement as tetragonal structure with the space group I4 1 /acd. The CrO 6 octahedrons elongate along c axis and rotate in ab plane. DC and AC magnetic susceptibility measurement results indicate spin glass behavior at low temperature. Temperature dependence of resistivity measurement results show Ca 2 CrO 4 is an insulator at both ambient condition and high pressure. C 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license