Hyperfine-Enhanced Magnetic Ordering in Singlet-Ground-State Systems

Abstract

It is shown that in systems with single-electronic ground states the simultaneous diagonalization of a hyperfine, as well as an exchange interaction, gives rise to an interference between these two effects which has important consequences on the properties of such a system. It is found, for example, that long-range order is now possible for values of the exchange below that previously thought necessary. Calculations are presented for the magnetic moment, heat capacity, susceptibility, and collective modes for a system involving praseodymium.