Mössbauer and Magnetic Studies of Co0.5Mn0.5Fe2O4 and Mn0.1Mg0.2Co0.7 Fe2O4 Nanoferrites

摘要

We report the magnetic properties of Mn0.5Co0.5Fe2O4 and Mn0.1Mg0.2Co0.7Fe2O4 nanoferrites. The compounds were synthesized by a glycol-thermal method with average particle sizes of about 13 nm and 8 nm, respectively. The Mössbauer measurements were done at 300 K. The distribution of cations between tetrahedral (A) and octahedral (B) sites is investigated. The Mössbauer spectra indicate ferrimagnetic behavior of the compound. Field cooled (FC) and zero field cooled (ZFC) magnetizations were performed by a Superconducting Quantum Interference Device (SQUID) magnetometer from 4–380 K. Variation of the magnetizations with the applied fields (up to 50 kOe) were recorded at isothermal temperatures 4, 50, 100, 200 and 300 K. An increase in FC magnetization is observed with increasing applied field. This is explained based on superparamagnetic behavior of the particles.