Nanoscale Coating of Silicon and Manganese on Ferrimagnetic Yttrium Iron Garnets

A uniform microstructure of Gd-substituted yttrium iron garnet (Y₂Gd₁Fe₅O₁₂) was obtained with additives of Si and Mn using a sol-gel coating process. Tetraethyl orthosilicate (TEOS) and manganese acetate were used as Si and Mn sources for the sol-gel coating procedure, respectively. TEM/EDS analysis confirmed the presence of a relatively uniform nanoscale coating of Si and Mn around each particle. High density and uniform microstructure were obtained after sintering at 1400°C in O₂ atmosphere. The density and grain size of the specimens depended on Mn content. The results were compared with materials fabricated without additives incorporated by the sol-gel coating procedure.