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

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 A degrees C under Ar/H-2 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.