Room Temperature Ferromagnetism in Powder Form of Sn₁__xCr_xO₂ (x = 0.01, 0.02, 0.03, 0.04 and 0.05) Solid Solution

Abstract

Structural and magnetic properties were investigated in the mixed powders of Sn_1−xCr_xO2 (x = 0.01, 0.02, 0.03, 0.04 and 0.05) in nominal composition. The lattice parameter observed in (110) x-ray diffraction indicates two step changes with increasing Cr content. The occupation of Cr ion at the interstitial position leads to elongation of the lattice parameter for x = 0.01 to x =0.03. Then, the Cr³⁺ ions are remarkably substituted into the Sn⁴⁺ ion site for x = 0.04 to x = 0.05, which results in shortening of the lattice. The lattice parameters for x = 0.01 and 0.02 are larger than x = 0.03 to 0.05. The room temperature ferromagnetism appeared in the sample with x = 0.01 and reaches maximum at the doping rate of x = 0.02; while the magnetization decreases for x > 0.02 was observed. Present study clearly shows the existence of correlation between appearance of ferromagnetism and the structural change.