Thermal conductivity of the amorphous and nanocrystalline phases of the beech wood biocarbon nanocomposite

• Published in: Physics of the solid state Vol. 56; no. 11; pp. 2348 - 2352
• Main Authors: Kartenko, N. F., Orlova, T. S., Parfen’eva, L. S., Smirnov, B. I., Smirnov, I. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2014; Springer
• Subjects: Diffraction; Physics; Physics and Astronomy; Solid State Physics; Thermal Properties; X-rays; Nanocrystalline Phase; Carb; Beech Wood; Carbon Skeleton; Entire Temperature Range
• ISSN: 1063-7834; 1090-6460
• DOI: 10.1134/S1063783414110158

Natural composites (biocarbons) obtained by carbonization of beech wood at different carbonization temperatures T carb in the range of 800–2400°C have been studied using X-ray diffraction. The composites consist of an amorphous matrix and nanocrystallites of graphite and graphene. The volume fractions of the amorphous and nanocrystalline phases as functions of T carb have been determined. Temperature dependences of the phonon thermal conductivity κ( T ) of the biocarbons with different temperatures T carb (1000 and 2400°C) have been analyzed in the range of 5–300 K. It has been shown that the behavior of κ( T ) of the biocarbon with T carb = 1000°C is controlled by the amorphous phase in the range of 5–50 K and by the nanocrystalline phase in the range of 100–300 K. The character of κ( T ) of the biocarbon with T carb = 2400°C is determined by the heat transfer (scattering) in the nanocrystalline phase over the entire temperature range of 5–300 K.