HIP BERYLLIUM - THERMAL EXPANSIVITY FROM 4-K TO 300-K AND HEAT-CAPACITY FROM 1-K TO 108-K

Linear thermal expansivity measurements from 4.2 to 302 K and heat capacity measurements from 4.6 to 108 K have been made on HIP (hot isostatic pressing) beryllium metal. The heat capacity data are in good agreement with previous data from 1.4 to 30 K for high purity single crystals. Our THETA-0 = 1485 (5) K also agrees well with that calculated from high-pressure elastic constant results. The linear thermal expansivity decreases rapidly with decreasing temperature from 1.13 x 10(-5) K-1 at 293 K, as would be expected for the large THETA-0, and becomes very small (< 10(-7) K-1) below 50 K. The expansivities below 108 K are consistent with a constant gamma-0-lat = 1.15 and with gamma-0-lat = 0.91 from the high-pressure elastic constant results.