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Thermal Diffusivity of Be 4 B, Be 2 B, and BeB 6
Author(s) -
HOLT J. B.
Publication year - 1974
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1974.tb10833.x
Subject(s) - thermal diffusivity , thermal conduction , analytical chemistry (journal) , materials science , thermal conductivity , boron , thermal , thermodynamics , chemistry , mineralogy , physics , organic chemistry , chromatography
The thermal diffusivities of polycrystalline Be 4 B, Be 2 B, and BeB 6 were measured by the flash method. Generally, the thermal diffusivities at a given temperature decrease with increasing boron content. The thermal diffusivities of Be 4 B, Be 2 B, and BeB 6 varied from 0.13 to 0.072 to 0.031 cm 2 /s, respectively, at 200°C and from 0.068 to 0.038 to 0.007 cm 2 /s at 1000°C. Heat transport in BeB 6 is expected to occur almost entirely by phonon conduction, whereas electronic conduction probably plays a major role in Be 4 B and Be 2 B. Analytical expressions for the thermal diffusivities (α) of Be 4 B and Be 2 B at 200° to 1000°C and of BeB 6 at 25° to 1500°C are: α(Be 4 B)=1/(5.83+9.05×10 3 T ), α(Be 2 B)=1/(10.92+1.40×10 2 T ), and α(BeB 6 )=5.60×10 4+5.72/ T +77.3/T 2 ‐4.09×10 4 /T 3 cm 2 /s.