Preparation and high-temperature conductive mechanism of Ni-modified SiHfBCN ceramic thin films

High-temperature multi-film layer sensors provide important technical support for monitoring key parameters in extreme environments. However, the lack of sensitive layer electrode materials with excellent high-temperature conductivity and structural stability limits their application in harsh working conditions. In this study, SiHfBCN(Ni) ceramic thin films with excellent electrical conductivity were prepared at a relatively low pyrolysis temperature by introducing Ni to chemically modify the SiHfBCN precursor. The conductive mechanism of the films was clarified through microstructural analysis. By regulating the Ni content, a smooth and uniform film morphology was obtained. By regulating the pyrolysis temperature, the catalytic effect of Ni was significantly enhanced, generating abundant various nanoparticles including graphitized carbon, core-shell structured Ni@C and HfC_xN_1-x nanoparticles within the amorphous matrix, forming multiple nanocomposite ceramic structures, and constructing an efficient three-dimensional conductive network. The minimum room-temperature resistivity decreased from 1494 Ω·cm before modification to 2.854 Ω·cm after modification. At temperatures up to 1200 °C, the films deliver enhanced electrical conductivity relative to room temperature and maintain stable morphological structure. These findings highlight the great application potential of SiHfBCN(Ni) thin films in the field of high-temperature thin-film electrodes.