NUCLEAR MAGNETIC ORDER IN SOLID HE-3

Over the past 20 years our understanding of cooperative magnetic phenomena in solid He-3 has expanded greatly. Starting from the concept of atomic exchange, the author explains how early experiments led to the abandonment of the naive Heisenberg nearest neighbor antiferromagnetic Hamiltonian, in favor of a multiple exchange model. He then describes the detailed experimental picture of the spin-ordered phases which has developed over the past decade, and the successes and failures of the multiple exchange model to explain the experimental results. Today solid He-3 is a powerful model magnetic system for extending our general understanding of magnetic order, and should continue to play an important role for many years to come.