Synthesis, characterization, resistivity and magnetoresistance of Ba2Fe1−xGaxMoO6 double perovskite

Abstract

Effect of Ga addition on structure, resistivity and magnetoresistance of Ba2Fe1−xGaxMoO6 (x = 0.0, 0.1, 0.25 and 0.3) double perovskite. The sol–gel procedure was used to synthesize Ba2Fe1−xGaxMoO6 double perovskite and consolidated at 1150 °C under Ar/H2 atmosphere. Single phase with cubic crystal structure confirmed for all the samples through X-ray diffraction studies. Variation of grain size behavior on the samples surface has been studied by scanning electron microscopy (SEM). The spectra from energy dispersive X-ray spectroscopy (EDS) showed that all the elements Ba, Fe, Ga, Mo and O are present in the samples and there are no impurities in the materials. Fourier transform infrared spectroscopy (FTIR) spectral analysis of samples produced three characteristic absorption bands of Mo–O and Fe–O vibrations in the wave number range 400–1000 cm−1 which confirmed the present materials are double perovskite phase. Magneto-resistance (MR %) of these samples reduce with the addition of Ga content at room temperature (RT). Whereas, MR% at 5 K exhibits opposite trend to the MR% at RT with the Ga-content. It is found that all samples show semiconductor behavior at 5 K and changes into metallic nature as temperature increases showing a semiconductor-metallic transition. This value is larger for composition x = 0.3 and smaller for parent compound.