Optical and magnetic properties of Gd Sr CrO (0 ⩽ x ⩽ 0.15).

Optical and magnetic properties of Gd Sr CrO (0  ⩽  x  ⩽  0.15) polycrystalline samples have been investigated to identify the role of Sr ion in GdCrO compound. Quantitative structural analysis using Rietveld refinement suggests the formation of single orthorhombic phase up to x  =  0.1 composition, and in addition, a secondary monazite-type structure of SrCrO arises for x  =  0.15 composition. Raman and Fourier transform infrared spectra also confirm the presence of SrCrO component for higher concentration of Sr ion. Mixed valence state of Cr such as Cr and Cr is obtained from x-ray photoelectron spectroscopy. The presence of Cr ion induces a reduction of optical band gap with increase of Sr content. The unoccupied states originate from Cr modify d-d transitions. Larger cell volume and breaking of magnetic exchange pathways through nonmagnetic element (Sr) weaken the strength of interaction and consequently lower Néel and spin reorientation temperatures.