Electrical conductivity of cellular Si/SiC ceramic composites prepared from plant precursors

Journal Article · Thu Feb 01 00:00:00 EST 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2433137· OSTI ID:20982676

Mallick, Debopriyo; Chakrabarti, Omprakash; Bhattacharya, Dipten; Mukherjee, Manabendra; Maiti, Himadri S; Majumdar, Rabindranath ^[1]

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1. Non-oxide Ceramics and Composites Division, Central Glass and Ceramic Research Institute, Kolkata 700 032 (India)

Electrical conductivity ({sigma}{sub dc}) of the cellular Si/SiC ceramic composites has been measured over a temperature range of 25-1073 K, while the thermoelectric power (S) has been measured over 25-300 K. Remarkably, these cellular compounds developed through the biomimetic route--where the ceramic system grows within a plant biotemplate retaining the imprint of structural intricacies of the native templates--are found to exhibit excellent mechanical, thermal, and electrical properties quite comparable to or even better than those of the systems prepared through the conventional ceramic route. The electrical conductivity, measured parallel ({sigma}{sub (parallel{sub sign})}) and perpendicular ({sigma}{sub (perpendicular{sub sign})}) to the growth axes of the native plants, depicts nearly temperature-independent anisotropy ({sigma}{sub (perpendicular{sub sign})})/{sigma}{sub (parallel{sub sign})}) of the order {approx}2, while the thermoelectric power is nearly isotropic. The charge conduction across the entire temperature regime is found to follow closely the variable range hopping mechanism. The conductivity anisotropy appears to be driven primarily by the unique microcellular morphology of the biotemplates, which can be exploited in many electrical applications.

• OSTI ID: 20982676
• Journal Information: Journal of Applied Physics, Vol. 101, Issue 3; Other Information: DOI: 10.1063/1.2433137; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
CERAMICS
CRYSTAL GROWTH
ELECTRIC CONDUCTIVITY
MORPHOLOGY
SEMICONDUCTOR MATERIALS
SILICON
SILICON CARBIDES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K