Crystal Structures And Properties Of Double Perovskites Sr-Ce-Fe-Mo-O-N System

In this paper, double perovskite Sr2 Fe Mo O6-xNx and Sr2-xCexFe Mo O6-xNx series sample had been successfully synthesized by solid-state reaction method. The crystal structures and magnetic properties of these samples were researched by X-ray powder diffraction(XRD) and vibrating sample magnetometer, respectively. We use the digital direct electrical bridge method to measure and analyse its performance of electricity. N content is determined by the formaldehyde method.The crystal structures of double perovskite Sr2 Fe Mo O6-xNx(t=0, 1, 4, 6, 9 h) series had been successfully synthesized all belong to tetragonal system. The space groups of these samples are all I4/mmm. The lattice volumes decrease with increasing content of N. The bond angles of Fe?(O,N)?Mo are 180.0°. The degree of order demonstrates an increase with ammonolysis time. With the increase of the magnetic field, the magnetic moment is not saturated in a 1.0 T magnetic field. During the analyze electrical performance in this series sample, we could find a obvious negative magnetic resistance effect. From the trend of the resistivity changes with magnetic field intensity, and extend along with the time passing ammonia, negative magnetoresistance effect gradually reduced. The biggest negative magnetic resistance is 7.44%(t=1 h).The crystal structures of double perovskite Sr2-xCexFe Mo O6-xNx(t=1, 4, 6, 9 h) series had been successfully synthesized all belong to tetragonal system. The space groups of these samples are all I4/mmm. The lattice volumes increase with ammonolysis time(increasing content of Ce), except that of ammonolysis 6 h. The bond angles of Fe?(O,N)?Mo are 180.0°. The degree of order demonstrates a decrease with ammonolysis time(increasing content of Ce). With the increase of the magnetic field, the magnetic moment is not saturated in a 1.0 T magnetic field. During the analyze electrical performance in this series sample, from the trend of the resistivity changes with magnetic field intensity, and extend along with the time passing ammonia and the increased doping content, negative magnetoresistance effect gradually reduced, The biggest negative magnetic resistance is 7.95%(t=1 h).