Structural and electromagnetic behavior evaluation of Nd-doped lithium-cobalt nanocrystals for recording media applications

Nano-crystalline Li0.5Co0.5NdxFe2-xO4 (x = 0.0, 0.035, 0.070, 0.105, 0.140, 0.175) ferrites have been synthesized via micro-emulsion technique. Thermal analysis, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), magnetometer analysis and a. c. electrical studies are employed to observe the impact of Nd3+ doping in Li0.5Co0.5Fe2O4 on crystallite size, spectral bands, dielectric and magnetic parameters. Thermal analysis depicts the weight loss with various temperatures and it illustrates that there is no further weight loss above 950 degrees C. XRD analysis establishes the formation of single phase cubic spinel structure. Although for x = 0.0 and thereafter for x >= 0.035 a peak of second phase (NdFeO3) occurs. The XRD data analysis revealed that the Nd substituted Li0.5Co0.5Fe2O4 ferrites revealed crystallite size 52.02-106 nm ranges. The lattice parameter and crystallite size show a nonlinear behavior. The FTIR data between 400 and 1000 cm(-1) defined the intrinsic cation vibrations of the characteristic spinel structure. The dielectric parameters are investigated in the range of 1 MHz-3 GHz frequency. A damping effect in the dielectric parameters is observed by Nd3+ incorporation and also by increasing the frequency. Magnetic measurements at room temperature exhibit an appreciable increase in the saturation magnetization and coercivity with the substitution of Nd3+ cations. Coercivity is in range of soft ferrite. The dominating effects of doping on dielectric properties propose that these nano-ferrites are useful in the fabrication of high frequency devices, whereas increase in magnetization and coercivity propose the use for high density recoding media. (C) 2015 Elsevier B. V. All rights reserved.