Long-range effective interactions and spin canting: A model for amorphous magnetism

Abstract
The onset of canting for a ferromagnet with one and two antiferromagnetic defect bonds has been studied analytically. For individual negative defect bonds which are unable to cause canting, there is a long-range effective dipolar-like interaction which determines whether or not the system will cant. An effective Hamiltonian is obtained which applies more generally. A canted state at low temperatures, but a collinear state at somewhat higher temperatures, can be expected on the basis of this effective Hamiltonian.