Role of pinning mechanism in co-precipitation derived cobalt rich, cobalt ferrite nanoparticles

摘要: Cobalt ferrite nanoparticles have been synthesized using a co-precipitation approach. Co:Fe precursor ratio is varied over certain window (1.05 to 1.2). It observed that the 1.15:2 gives better phase control but poor coercivity. On other hand, 1.05:2 results in substantially coercivity values (274kA/m; almost 300% value reported for co-precipitated cobalt by Praveena et al.), moderate BH product maximum (2.25 kJ/m3; ~ comparable many reports on so far). The with best are annealed at 873K varying durations (2, 4, 6, 12 hrs). drops drastically (almost 80%) after annealing 2 hours. However thereafter and saturation magnetization improves marginally increasing duration of annealing. These studies, along thermogravimetric analysis, infrared spectroscopic indicate hydroxide nanophase based flux pinning mechanism grain boundary plays an important role explaining magnetic property trends. believed this result will be generically helpful developing soft chemically derived ferrites higher (BH)max. develop plausible applications use pinning, materials device processing methods need explored.