[ACS Appl. Mater. Interfaces] Magnetoceramics from the Bulk Pyrolysis of Polysilazane Cross-Linked by Polyferrocenylcarbosilanes with Hyperbranched Topology
writer：J. Kong*, M.M. Kong, X.F. Zhang, L.N. An
keywords：Polyferrocenylcarbosilanes
source：期刊
specific source：ACS Appl. Mater. Interfaces, 2013, 5: 10367-10375
Issue time：2013年
In this contribution, we report a novel strategy for the synthesis of nanocrystal-containing magnetoceramics with an ultralow hysteresis loss by the pyrolysis of commercial polysilazane cross-linked with a functional metallopolymer possessing hyperbranched topology. The usage of hyperbranched polyferrocenylcarbosilane offers either enhanced ceramic yield or magnetic functionality of pyrolyzed ceramics. The ceramic yield was enhanced accompanied by a decreased evolution of hydrocarbons and NH3 because of the crosslinking of precursors and the hyperbranched cross-linker. The nucleation of Fe5Si3 from the reaction of iron atoms with Si?C?N amorphous phase promoted the formation of α-Si3N4 and SiC crystals. After annealing at 1300 °C, stable Fe3Si crystals were generated from the transformation of the metastable Fe5Si3 phase. The nanocrystal-containing ceramics showed good ferromagnetism with an ultralow (close to 0) hysteresis loss. This method is convenient for the generation of tunable functional ceramics using a commercial polymeric precursor cross-linked by a metallopolymer with a designed topology.