Thermodynamic Properties and Melting of Solid Helium

摘要: The internal energy at O?K was calculated from the experimental data and found to be in good agreement with theoretical values based on Slater-Kirkwood potential, using 8RO as an estimate of zero-point (0 being Debye characteristic temperature). A first-order transition solid revealed; its equilibrium line cuts melting curve 14-90K moves higher temperatures densities. heat is very small, about 0-08 cal/mole. assumed correspond a change crystal structure hexagonal cubic close-packed. At highest pressure helium compressed less than half volume under conditions absolute zero, 0 increased five times. It hence possible test Lindemann formula for single substance over wide range. fit satisfactorily, although value constant it differed somewhat classical value.