Accession Number : AD0613207

Title :   NUCLEAR SUSCEPTIBILITY OF SOLID HELIUM-3,

Corporate Author : DUKE UNIV DURHAM N C

Personal Author(s) : Thomson,A. Low ; Meyer,Horst ; Dheer,Prakash N.

Report Date : 11 JUL 1963

Pagination or Media Count : 10

Abstract : Measurements of the nuclear susceptibility of solid He3 in the alpha phase between 0.07 and 1.7K are presented. The purity of this helium was better than 99.95%. All the results could be represented by a Curie-Weiss law chi = C/(T + 0) indicating an antiferromagnetic exchange. While theta is smaller than about 0.01K at molar volumes larger than 22 cu cm, it appears to increase systematically when the density increases further. The magnetic exchange between the nuclei, as deduced from our data, is fairly consistent at molar volumes above 22 cu cm with that obtained from specific heat and relaxation measurements. The higher density data, however, must be regarded as very tentative, in view of their disagreement with other data and theoretical expectations and are not presented in detail. Measurements of the longitudinal relaxation time were also carried out. In particular, for V = 19.5 cu cm/mole, T sub 2 was found to increase approximately as exp (2/T) below 1K, in contradiction with relaxation data of Reich, who found T sub 1 to be constant in this range. New susceptibility data are also presented for a solution of 99.0% He3 1% He4 and a tentative explanation is given to account for the difference with the results on the 'pure' He3. A method for measuring the pressure inside the solid He3 cavity is described. On the basis of these measurements, it is argued that the phase boundary in the V-T plane is unlikely to bend upwards at temperatures below 0.8K, as deduced from Reich's relaxation measurements. (Author)

Descriptors :   (*NUCLEAR PROPERTIES, MAGNETIC PROPERTIES), (*HELIUM, NUCLEAR PROPERTIES), (*SOLIDIFIED GASES, HELIUM), CRYOGENICS, NUCLEAR SPINS, SPECIFIC HEAT, ANTIFERROMAGNETISM

Distribution Statement : APPROVED FOR PUBLIC RELEASE