Synthesis and characterizations of Nd3+ doped Sr Fe12O19 nanoparticles

This is the first report ever on Nd3+ doped M-type hexaferrite nanoparticles: SrNdxFe12-xO19 (0 <= x <= 1) prepared by citrate precursor using the sol-gel technique followed by gel to crystallization. The influence of the Nd3+ substitution, Fe3+/Sr2+ molar ratio and the calcination temperature on the crystallization of ferrite phase have been examined using powder X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), inductance capacitance resistance meter bridge (LCR) and vibrating sample magnetometer (VSM). The structural analysis reveals that the Nd3+ ions rearrange themselves in the host lattice without disturbing the parent lattice and Fe3+/Sr2+ molar ratio less than 12 is more favorable to achieve single phase hexaferrite at calcination temperature 900 degrees C for 4 h. Mid-IR analysis confirms that Nd3+ occupies the octahedral site. Detailed studies of electrical properties of prepared materials have been investigated in the frequency range 100-1000 Hz at room temperature by LCR meter and two probe technique. The result shows that the electrical properties strongly depend upon the frequency of applied field and dopant concentration. The magnetic measurements showing a considerable improvement in coercivity with the substitution of Nd3+ on iron sites, while the unsubstituted hexaferrites have highest value of specific saturation magnetization. (C) 2013 Elsevier B.V. All rights reserved.