High temperature electrical and thermal properties of activated bamboo charcoal/C12A7 mayenite composite prepared by carbon diffusion process

Abstract

Abstract Activated carbon from bamboo charcoal (BC) was diffused into the C12A7 mayenite compound via carbon diffusion process for synthesizing BC and C12A7 composite (BC/C12A7 composite). The BC/C12A7 composite was fabricated by carbon diffusion at holding time 5, 10 and 20 h for investigating electrical and thermal properties at high temperature. Result of XRD revealed the C12A7 structure and confirmed by Raman spectrum. Obtained energy gap showed at 4.93, 5.26, 5.19 and 5.09 eV at holding times of 0, 5, 10 and 20 h, respectively. Electrical conductivity significantly increased with increasing temperature and increased as a function of increasing holding time. Carrier concentration showed approximately 1.27 × 1017, 1.32 × 1017 and 2.76 × 1017 cm−3 of 5, 10 and 20 h, respectively. Temperature dependence of thermal conductivity showed as proportion of T−1 due to phonon-phonon scattering of Umklapp process. The thermal conductivity decreased from pristine C12A7 approximately 0.4 W m−1 K−1 in all BC/C12A7 composite samples.