Effect of the graphitization level of the free carbon on the temperature sensitivity of silicon carbonitride‐based pressure sensors. Issue 10 (1st March 2021)

• Record Type: Journal Article
• Authors: Yu, Yuxi; Huang, Chenhao; Xu, Jie; Zhu, Jian; Cong, Minghui; Song, Jingyuan; Xia, Shengnan
• Is Part Of: Journal of the American Ceramic Society. Volume 104:Issue 10(2021)
• Page Start: 5067
• Page End: 5076
• Publication Date: 2021-03-01
• Subjects: conductivity -- polymer‐derived ceramics -- precursor infiltration and pyrolysis -- temperature sensitivity -- wireless passive pressure sensor; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.17737
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: Polymer‐derived ceramics (PDCs) have recently attracted an increasing attention because of their applications for wireless passive pressure sensors in the harsh environment. However, due to the effect of temperature on the frequency of PDC‐based wireless passive pressure sensors, it is not beneficial to accurate measurement of pressure. In this paper, a dense polymer‐derived silicon carbonitride (SiCN) ceramic was prepared by precursor infiltration and pyrolysis (PIP) technique to reduce the temperature sensitivity of PDC–SiCN‐based pressure sensor. The open porosity and density of SiCN ceramics varied from 13.34% and 1.89 g/cm 3 without PIP process to 3.24% and 2.09 g/cm 3 after three PIP cycles, respectively. Raman spectroscopy revealed that the level of graphitization of free carbon in dense SiCN ceramics is higher than that in porous SiCN ceramics, which would lead to an increase in the conductivity of dense SiCN ceramics. After three PIP cycles, the conductivity increased by almost two orders of magnitude from 3.01E − 10 to 1.28E − 08 S/cm. In addition, SiCN ceramic discs after PIP cycles and without PIP were applied to wireless passive pressure sensor based on resonator, which were tested at high temperature, respectively. Results confirmed that the temperature sensitivity of PDC–SiCN‐based pressure sensor decreased from 220.5 to 50.8 kHz/°C by PIP process. Abstract : The couductivity variation with temperature of SiCNs and the temperature sensitivity of SiCN‐based pressure sensors are reduced by PIP process.