Dipolar Antiferromagnetism and Quantum Criticality in LiErF 4

Dropping a Dimension? In most magnetic materials, the exchange interaction causes the spins on the neighboring sites of a crystal lattice to align. In the absence of exchange interactions, dipolar interactions, which are highly orientation dependent, are also expected to be able to cause magnetism. Kraemer et al. (p. 1416 ) present evidence for antiferromagnetism in a dipolar-coupled material, LiErF 4 . Although a three-dimensional system, its critical behavior was more reminiscent of a two-dimensional material.