0.4Zn_0.6Cr_0.5Gd_xFe_1.5-xO₄ ferrite nanoparticles]]>

摘要

We report on the influence of Gd3+ and Cr3+ doped nanocrystalline ferrite materials with a general formula of Ni_0.4Zn_0.6Cr_0.5Gd_xFe_1.5-xO₄ (where x = 0.00, 0.02, 0.04, 0.06) have been synthesised by solution combustion method using oxylyl dehydrazide (ODH) as a fuel. The structural and magnetic properties of the samples were characterised by X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy and vibrating sample magnetometer (VSM). The XRD analysis of the as synthesised sample reveals single phase with spinel cubic structure (Fd-3m space group) and the average crystalline sizes of the nanoparticle were estimated using Debye Scherrer's formula and found to be 19-34 nm. The FTIR results show the functional groups of Ni-Zn ferrite the two main spectroscopic bands corresponding to lattice vibrations were observed in the wavelength range from 300 cm-1 to 1000 cm-1. The absorption bands at 577 cm-1 and 380 cm-1 were assigned to tetrahedral (A) and octahedral (B) groups respectively in all the samples. Also IR spectrum shows that Gd3+ occupies the octahedral B-sites. Magnetic parameters such as saturation magnetisation (M_s), remanence magnetisation (M_r) and coercivity (H_c) were measured from the hysteresis loop. The saturation magnetisation increases for x = 0.00, 0.02 and decreases. This kind of ferrites could be used to prepare magnetic fluids and also used for high frequency applications.]]>