High saturation magnetization, low coercivity and fine YIG nanoparticles prepared by modifying co-precipitation method

摘要

Nanoparticles with their specific properties newly have drawn a great deal of attention of researchers (Khezri et al., 2012 [1]; Khezri et al., 2013 [2]; Lu et al., 2007 [3]). Yttrium iron Garnet magnetic nanoparticles (YIG-NPs) are promising materials with novel applications in microwave, spintronics, magnonics, and magneto-optical devices. However, achieving stable and remarkable magnetic YIG-NPs has been remaining as a great challenge. In this paper, synthesized YIG-NPs by modifying co-precipitation (MCP) method is reported. Structural and magnetic properties of final products are compared to those of the materials prepared by citrate-nitrate (CN) method. Smaller crystals and particle size have been found by MCP method comparing to that of synthesized by CN method. Using a relatively low annealing temperatures for both sets of samples (similar to 700 degrees C), the final YIG samples prepared by MCP method show more structural purity than those made by CN method. Higher saturation magnetization (M-s) and lower coercivity (H-c) are observed in MCP YIG sample (23.23 emu/g and 30.1 Oe) than the CN prepared YIG sample (16.43 emu/g and 44.95 Oe). The Curie temperature is measured to be 569 degrees C for the MCP YIG sample determined from set of Ms measurement at different temperatures ranging from 80 to 600 K. These findings lead to significant improvement in quality of synthesized (synthetic methods) YIG-NPs.