The thermal diffusivity of pyrolytic graphite at high temperatures

✍ Scribed by Takaho Tanaka; Hiroshige Suzuki

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 496 KB
• Volume: 10
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(72)90323-5

✦ Synopsis

The thermal diffusivity of three pyrolytic graphites was measured using the modulating electron beam method over the temperature range from 1300°C to 1900°C. One of the specimens was as-deposited at 2500X, and the others were the same heattreated at 3000°C after deposition. The mean free path of phonons was estimated by analysis of the experimental data. The mean free path seems to be indepevdent of temperature in the direction perpendicular to the deposition plane; being 4.8 A for the as-deposited specimen, 6.4 and 7.4 A4 for the two heat-treated ones, respectively. The temperature dependence of the mean free path parallel to the deposition plane cannot be expressed in analytical form. However, a monotonic decrease from 91 A at 1330°C: to 56 A at 1980°C is indicated by a tentative approximate calculation.