Annealing dependence of magnetic properties in nanostructured particles of yttrium iron garnet prepared by citrate gel process

Abstract

Yttrium iron garnet (YIG) particles were first synthesized using a low-temperature method based on the citrate gel process. The annealing temperature dependence of the magnetic behaviour was investigated by means of transmission 57Fe Mössbauer spectrometry and DC magnetic measurements. The as-prepared particles behaves as an amorphous-like structure. Annealing treatments cause aggregation and crystallization of particles. For low annealing temperatures, one can suggest a nanostructured behaviour of the YIG particles, which progressively disappears when the annealing temperature increases. Depending on the annealing temperature, YIG nanostructured particles of different size, in the range 50–700 nm were obtained. The values of the saturation magnetization as well as the Curie temperature for the YIG particles are close to those observed for well-crystallized YIG.