Comprehensive study of MFe2O4 (M=Co, Ni, Zn) nanostructures prepared by co-precipitation route

Abstract

The phase analysis and average crystallite size of 11.8, 3.1, and 24.7 nm for MFe2O4 (M=Co, Ni, Zn) nanoparticles (NPs) were analyzed by X-ray diffraction (XRD) patterns, respectively. The spherical and nanoplatelets morphology of MFe2O4 (M=Co, Ni, Zn) was observed by High-Resolution Transmission electron microscopy (HRTEM). The peaks of Fe (2 P3/2), Fe(2 P1/2), Co (2 P3/2), Co(2 P1/2), Ni (2 P3/2), Ni (2 P1/2), Zn (2 P3/2), Zn (2 P1/2) and O (1 S) of the prepared nanostructures corresponding to octahedral and tetrahedral sites was observed X-ray photoelectron spectroscopy (XPS) spectra, respectively. Saturation magnetization of 37.4, 18.2, and 15.3 (emu/g) and coercive field of 525, 35.2, and 29.7 Oe of the prepared MFe2O4 (M=Co, Ni, Zn) nanostructures was recorded by M-H analysis at the applied field of ± 7 T. The shifting of the blocking temperature towards lower scale of about 300 K, 150 K, and 55 K for CoFe2O4, NiFe2O4, and ZnFe2O4 nanostructures was determined by Zero field-cooled (ZFC) and field-cooled (FC) spectra, respectively. Spin-spin relaxation time 0.1677 × 10−15, and 0.0482 × 10−15 (s) and Spin-lattice relaxation time 0.829 × 10−14, and 2.865 × 10−14 (s) have been evaluated for NiFe2O4 and Zn Fe2O4 NPs, respectively from EPR spectroscopy. Super-paramagnetic time of 0.134 × 10−10, and 5.703 × 10−10 (s) was estimated from the EPR spectrum of the samples exhibiting less time required for NiFe2O4 than ZnFe2O4 NPs. The prepared NPs showing the superparamagnetic property can be used in biomedical applications such as drug delivery and magnetic resonance imaging (MRI).