Crystal structures and phase transitions of Sr2CrSbO6

Sr2CrSbO6 was synthesized by the conventional solid-state reaction process. X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD) has been used to reinvestigate the structure at room temperature and to study the phase transitions at high- and low-temperature. Rietveld analysis revealed that Sr2CrSbO6 crystallizes at room temperature in a monoclinic system having a space group I2/m, with a=5.5574(1) Å; b=5.5782(1) Å; c=7.8506(2) Å and β=90.06(2), no P21/n space group as was previously reported. The high-temperature study (300–870 K) has shown that the compound presents the following temperature induced phase-transition sequence: I2/m–I4/m–Fm-3m. The low-temperature study (100–300 K) demonstrated that the room-temperature I2/m monoclinic symmetry seems to be stable down to 100 K.