Structural and magnetic properties of Cr2O3 at high pressure

Abstract The structural and magnetic properties of Cr 2 O 3 have been studied by means of X-ray and neutron powder diffraction at high pressures up to 35 GPa. The lattice compression of the rhombohedral crystal structure of R 3 ¯ c symmetry is slightly anisotropic with anomaly in the pressure behavior of the c/a parameters ratio at P  ≈ 20 GPa of presumably magnetic nature. The oxygen octahedra around chromium ions become more symmetric with close values of shared and unshared bonds under high pressure. The antiferromagnetic structure of Cr 2 O 3 remains stable in the studied pressure range up to 35 GPa. The pressure coefficient of the Neel temperature, (1/ T N )( dT N /dP ) = + 0.0091 GPa −1 , is significantly less in comparison with perovskite-like compounds containing Cr 3+ and Mn 4+ ions of similar electronic configuration.