Gd induced the variations of anti-site defect and magnetism in the double perovskite oxides Sr2FeMoO6

Crystal structure, magnetic and transport properties of Sr2−xGdxFeMoO6 (0 ≤ x ≤ 0.25) are investigated. The anti-site defect in this series can be adjusted by rare-earth element of Gd. Gd3+ replace for Sr2+ results in the increase of anti-site defect due to the differences in valence and size between Gd3+ and Sr2+. The moment of Gd3+ may be in canted structure. The effective moment of Gd3+ is about 1.5 μB/Gd3+, which is anti-parallel to that of Fe3+. The moment of Gd3+, Fe3+, and Mo5+/Mo4+ interact each other, and play important roles on transport and magnetic properties.