Magnetic properties of amorphous silicon carbonitride-based magnetoceramics synthesized using phenyl-substituted polysilazane as a precursor

Abstract

Magnetoceramics composed of pure α-Fe crystals grown in an amorphous silicon carbonitride matrix were prepared using phenyl-silsesquiazane (PSSQZ) and iron oxide (Fe3O4) as precursors. Magnetoceramics with commercial polysilazane were also synthesized for comparison. The PSSQZ induced growth of only α-Fe crystals in the magnetoceramics because of the high C content of the phenyl group of PSSQZ and the ability of the precursor to control the Si content; moreover, Fe silicide was not formed. In addition, the effect of the chemical composition of the precursor on the crystal phase growth was confirmed via ab initio thermodynamic calculations. The growth of pure α-Fe crystals resulted in improvements in magnetic saturation from 10.62 to 27.82 emu/g. This study showed that the microstructure of the magnetoceramics could be controlled according to precursor composition, resulting in an improved magnetic property.