Structural, ferromagnetic, ferroelectric, and bio-medical behaviour of yttrium doped strontium hexaferrite (SrFe_12-xY_xO₁₉) nano materials, assisted with sol-gel cost effective technique

Abstract

Yttrium substituted strontium hexaferrite with X= (0.25-1.0), is synthesized using an economical sol-gel technique. The reflected planes in the XRD patterns justify that samples possessed hexagonal symmetry (P63/mmc space group). Crystallite size and strain calculations for SrFe12-xYxO19 samples were performed with a W-H plot. Lattice constants changes minutely but regularly with Y3+ composition. The morphological structure of the sample has been visualized from SEM micrographs. TEM, HRTEM and SAED has been performed for confirming the lattice fringe distance, grain size of nanoparticles (NPs) and diffraction planes. Grain size is found to be 44.15 nm and 37.27 nm for X=0.00 and X=1.0 composition of Y3+. Raman spectral pattern exhibited that all the peak of the synthesized sample is indexed to Raman vibration modes and strontium hexaferrite (SHF) structure. FTIR analysis supports the stretching of metal-oxygen bonding and is helpful in finding force constant and bond length of samples. The highest luminescent peaks is observed at 481 nm. The direct band gap (Eg) is found to decrease from 2.3 eV-1.93 eV with Y3+ concentration. With an increase of Y3+ concentration, Ms and Mr parameters decrease systematically while coercivity value increases drastically from 5983-6595 Oe, which is a novel works. The occupancy of Y3+ ions in SrFe12-xYxO19 lattice obstructs electrical leakage to generate remnant polarization (Pr) and coercive polarization (Pc) of values 25.45 μC/cm2 and 2.91 kV/cm respectively. Moreover, cytotoxicity assay reveals that at lower concentrations up to 250µg/ml the synthesized material SrFe12-xYxO19 for X=0.00 and X=1.0 promotes the growth of cell and hence represents non- toxic and biocompatible behavior with cell. Hence anticipation can be made that it may be used for biological and biomedical applications such as bone replacement, magnetic drug delivery, and coating on metal implants. Thus, improved physical properties of Y3+ doped SHF nanomaterials pave its way for promising applications.