Jaan Oitmaa - The University of NSW
Models of ferrimagnetism
Ferrimagnets are materials in which, at low temperatures, different sublattices have net magnetic moments which are antiparallel but do not cancel. This can be due to different numbers of ions on each sublattice or, more usually, different ionic moments. The temperature dependence of the sublattice moments will be different, and it is possible for the total moment to pass through zero at a particular temperature below the ordering temperature. This is called a compensation point.
I will describe a number of mixed spin ferrimagnetic Ising models which show compensation points. These include simple decorated models which can be solved exactly, a Monte Carlo simulation, and some preliminary work on the mixed spin (1/2,1) square lattice using high- and low-temperature series.