부산대학교 도서관

Sc 3+ doped Mn 0.5 Zn 0.5 Sc y Fe 2−y O 4 (y=0.00, 0.01, 0.03 and 0.05) nanoparticles were synthesized by solution combustion method using mixture of fuels were reported for the first time. The mixture of fuels plays an important role in obtaining nano crystalline, single phase present without any heat treatment. X-ray diffraction (XRD) results confirm the formation of the single-phase ferrites which crystallize in cubic spinel structure. The Fourier transform infrared spectra (FTIR) exhibit two prominent bands around 360 cm −1 and 540 cm −1 which are characteristic feature of spinel ferrite. The transmission electron microscope (TEM) micrographs revealed the nanoparticles to be nearly spherical in shape and of fairly uniform size. The room temperature impedance spectra (IS) and vibrating sample magnetometry (VSM) measurements were carried out in order to study the effect of doping (Sc 3+ ) on the characteristic properties of Mn-Zn ferrites. Further, the frequency dependent dielectric constant and dielectric loss were found to decrease with increasing multiple Sc 3+ concentration. Nyquist plot in the complex impedance spectra suggest the existence of multiple electrical responses. Magnetic measurements reveals that saturation magnetization (M s ), remnant magnetization (M r ), magnetic moment (η B ) and magnetic particle size (D m ) increase with Sc 3+ ion concentration up to x=0.03 and then decrease. The values of spin canting angle (α Y-K ) and the magnetic particle size (D m ) are found to be in the range of 68–75° and 10–19 nm respectively with Sc 3+ concentration. The room temperature Mössbauer spectra were fitted with two sextets corresponding to ions at tetrahedral (A-) and octahedral (B-) sites confirms the spinel lattice. The ferromagnetic resonance (FMR) spectra's has shown that high concentration of scandium doping leads to an increase in dipolar interaction and decrease in super exchange interaction. [ABSTRACT FROM AUTHOR]