Metallic behavior induced by slight N doping in Sr2FeMoO6 double perovskite compound

The N-doped compounds with double perovskite structure were synthesized by ammonolysis method and are characterized by means of X-ray diffraction, magnetic and electrical resistivity measurements. The effect of dopant on the crystal structure, magnetic properties and electrical behavior was studied. Rietveld analysis shows that for N-doped samples the unit-cell parameters, a and c , first decrease, then increase with ammonolyzed time. Thermal magnetization shows that the spontaneous magnetization for all samples follows Bloch’s law in low temperature range. The spin wave stiffness constant, Dsw, increases with ammonolyzed time from 0 to 8 h, followed by a sharp decrease with ammonolyzed time from 8 to 10 h. Isothermal magnetization for N-doped samples demonstrates that the saturation magnetic moments at different temperatures first increase, then decrease with N doping. The resistivity increases with ammonolyzed time from 3 to 10 h. For slight N-doped samples the electrical resistivity demonstrates metallic behavior and electrical transport behavior for all samples shows the disordered characteristic. The degree of B-site cationic order in N-doped samples is lower than that in N-undoped sample.