Crystal Structures And Properties Of Double Perovskites Ca-La-Fe-Mo-O-N System

In this paper, Ca₂FeMoO_6-xN_x and Ca2-xLaxFeMoO6-x Nx series with double perovskite structure had been successfully synthesized at 1100 ? by solid-state reaction processing. The effect of dopant on the crystal structure, magnetic properties and electrical behavior was studied. The crystal structures and magnetic properties of these samples were characterized by X-ray diffraction?XRD? and Vibrating sample magnetometer, respectively. We use the digital direct electrical bridge method to measure its performance of resistance. N content is determined by the Kjeldahl Nitrogen Determination method.Ca₂FeMoO_6-xN_x?x = 0, 0.594, 0.680, 0.765, 0.830? series with double perovskite structure had been successfully synthesized. The crystal structure is monocline system, space group is P21/n, with a = 5.418 ?, b = 5.531 ?, c = 7.716 ?, ?= 90.06°. Using refinement respectively by Fulprof software, we know that the series of the experimental value of all samples and the theoretical value are in accord with relatively good. The lattice volume declines with content of N. The degree of order increases first and then decreases with content of N. The spontaneous saturation magnetization?coming from hysteresis loop? declines with increasing of the temperature. During the analyze electrical performance in this series, the resistivity increases with content of N. From the resistivity changes with magnetic field, the obvious magnetoresistance effect is found in all the samples. From the trend of the resistivity changes with temperature rising, the obvious negative magnetoresistance effect is found in all the samples.Ca_2-xLa_xFeMoO_6-xN_x?x = 0, 0.594, 0.680, 0.765, 0.830? series with double perovskite structure had been successfully synthesized. The crystal structure is monocline system, space group is P21/n. with a =?5.484⁵.512? ?, b =?5.560 5.578? ?, c =?7.794 7.827? ?, ?=?89.93 90.05?°. Using refinement respectively by Fulprof software, we know that the series of the experimental value of all samples and the theoretical value are in accord with relatively good, too. The lattice volume decreases with N doping?the increasing content of La?. The saturation magnetization decreases with La doping?the increasing content of N?. And the spontaneous magnetization decreases with temperature increasing.