HEAT-CAPACITY STUDIES AT LIQUID HELIUM TEMPERATURES AND BELOW PART I:THE ALKALI METALS PART II:SMALL PARTICLES OF MAGNESIUM OXIDE

摘要

The heat capacity of two samples of two samples of magnesium oxide powder was measured from 1.5 through 4.0 °K. One sample had a specific surface area of l66 m /g and the other, 13.1 m2 /g. The heat capacity of both samples could be represented by the sum of a T and a T term. The T3 term is the usual volume-dependent term representing the total heat capacity in a macrocrystalline sample. The T 2 term is surface-dependent term and appears only in samples with high surface-to-volume ratios. This term was compared with various theories of surface heat capacities for both samples.