Nickel silicide nanocrystal-containing magnetoceramics from the bulk pyrolysis of polysilazane and nickelocene

Nickel silicide nanocrystal containing Si–Ni–C–N multiphase ceramics were synthesized by bulk pyrolysis of the mixture of polysilazane (PSZ) and nickelocene (NiCp₂) at high temperature. The pyrolysis behavior of the precursors was investigated by TGA/DSC-Mass Spectrometry. The yield of the ceramic containing NiCp₂ precursor was increased by 8–10% compared to pure PSZ. Nickel silicide nanocrystal containing ceramics were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. The NiCp₂ in polymeric precursors induced the formation of α-Si₃N₄, SiC, graphitic carbon, and Ni₂Si at 1100 °C. Nickel silicide nanocrystals containing ceramics exhibited soft magnetism with ultralow hysteresis loss offering a convenient cost effective approach for the preparation of tunable transition metal-containing ceramics using a commercial inexpensive polymeric precursor of NiCp₂.