Low temperature acoustically measured specific heats and elastic constants of four technical polymers

✍ Scribed by A.D. Athougies; B.T. Peterson; G.L. Salinger; C.D. Swartz

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 380 KB
• Volume: 12
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(72)90009-4

✦ Synopsis

The velocity of longitudinally and transversely polarized 10 MHz sound waves has been measured in four technical polymers (nylon, Teflon, and two epoxy resins) between 4 and 100 K. The values of the specific heat divided by T 3 calculated from these measurements is considerably less than the values measured calorimetrically below 4 K. This discrepancy is due to the existence of localized modes which make the extrapolation of specific heat measurements in amorphous materials extremely dangerous Low temperature values of the bulk and shear modufi well as Poisson's ratio are also presented.