On the Magnetic Properties of Liquid He3

Abstract

The object of this paper is to investigate the possibility that liquid He₃ might have a tendency toward nuclear ferromagnetism in the approximation where this fluid is considered to be an antisymmetrical collection of atoms having an angular momentum of ℏ/2 and a finite nuclear magnetic moment. In the rather crude approximation where the motion of the individual atoms is described with the help of plane de Broglie waves, the exchange energy, originating in the interatomic mutual potential energy of He₃ atoms, favors the parallel alignment of all spins at the temperature of absolute zero. The total energy of the fluid is, however, smaller in the antiferromagnetic configuration because its kinetic energy is smaller than in the ferromagnetic configuration. To the approximation of these studies then, liquid He₃ does not show nuclear ferromagnetism. Its nuclear paramagnetism is then discussed.