Specific heat of halocarbon 25-5s grease (polychlorotrifluoroethylene in silica gel) below 4.5K

Abstract The specific heat for halocarbon 25-5s grease is reported for the temperature range 1.8 to 4.5 K. The grease is a commercially prepared mixture of polychlorotrifluorethylene in silica gel (PCTFE-SG). It can be used to protect samples which are reactive to the atmosphere. Its suitability for such use when making specific heat measurements was investigated. The specific heat at low temperatures was well described by the expression, C = 0.283 T 3 mJ gm −1 K −4 . It was found to be suitable for samples with relatively large low temperature specific heats.