Microstructural Analysis and Effect of Spin-Canting on Magnetic Attributes of Single-Phase Polycrystalline Cobalt Ferrite Nanoparticles.

Cobalt ferrite (CF) nanoparticles (CFNPs), prepared using citrate precursor method, were characterized using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Vibrating-sample Magnetometer (VSM) techniques to obtain their microstructural, morphological, and magnetic properties. The analysis of the obtained XRD data confirmed the spinel structure and phase purity of CFNPs with a crystallite size of ~ 26 nm. The SEM micrograph revealed the formation of nonuniform-sized grains, confirming the polycrystalline nature of the synthesized CFNPs. The VSM data revealed that the CFNPs exhibited moderate specific saturation magnetization (~ 59 emu/g), moderate specific remanent magnetization (~ 24 emu/g), and slightly higher coercivity (~ 601 Oe). A significant decrease in the specific saturation magnetization of the CFNPs was observed compared to bulk CF counterparts. This study correlates the observed decrease in the specific saturation magnetization to the presence of a degree of inversion (x) arising from less-than-ideal cation distribution for the inverse spinel CF system. This study also reports the existence of a nontrivial deviation of the magnetic order from the ideal, collinear, antiparallel spin structure of the prepared CFNP system. The presence of the Yafet-Kittel type of magnetic order, resulting from the nanoscale crystallite size, cation distribution, intra-sublattice exchange interactions, and spin reorientation, is established. The corresponding values of the Yafet-Kittel angles of the spin-canted magnetic order of the CFNP system have been empirically determined and reported. [ABSTRACT FROM AUTHOR]