Influence of temperature on structural and magnetic properties of Co0·5Mn0·5Fe2O4 ferrites

• Published in: Bulletin of materials science 2011-12, Vol.34 (7), p.1415-1419
• Main Authors: Ramay, S. M., Saleem, Murtaza, Atiq, S., Siddiqi, Saadat A., Naseem, S., Sabieh Anwar, M.
• Format: Article
• Language: English
• Subjects: Annealing; Chemistry and Materials Science; Citric acid; Coercivity; Crystallites; Engineering; Ferrites; Lattice parameters; Magnetic properties; Materials Science; Room temperature; Sol-gel processes
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/s12034-011-0337-4

Co 0·5 Mn 0·5 Fe 2 O 4 ferrites have been synthesized using a single-step sol-gel auto-combustion method in which the metal nitrate (MN)-to-citric acid (CA) ratio was adjusted to 0.5: 1 and pH to 7, respectively. The structural and magnetic properties of as-burnt and annealed samples were studied as a function of temperature. The inverse spinel structure was confirmed by X-ray diffraction (XRD) and crystallite size was estimated by the most intense peak (311) using Scherrer’s formula. Contrary to earlier studies reported in the literature, both as-burnt and annealed samples exhibit crystalline behaviour. Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM) with field strengths up to ±10 kOe. Lattice constant and crystallite size increased as the annealing temperature was increased. However, the coercivity ( H c ) initially increased and then decreased with the increase of crystallite size. The variation in coercivity is ascribed to the transition from a multi-domain to a single-domain configuration.