It is shown by a general theoretical argument that the variation of the magnetic specific heat of a ‘simple’ antiferromagnet, in particular the singular behaviour in the region of the transition, should be closely similar to the behaviour of the function ∂(χT)∂T, where χ is the zero-field susceptibility. This conclusion is compared with the experimental results for MnO and MnF2 and its general implications for the shape of the susceptibility curve near the transition are discussed.

Relation between the specific heat and susceptibility of an antiferromagnet

Antiferromagnetic susceptibility of the plane square and honeycomb ising lattices

Progress in the theory of lattice statistics is reviewed with emphasis on the use of series expansions to study the critical behavior and on the exact results obtained by transformation theory. Recent work is reported which indicates that the magnetization of the three‐dimensional Ising model vanishes as (Tc − T)β with β≃516, while the low‐temperature susceptibility diverges as (Tc − T)−γ with γ=54(γ=74 in two dimensions). An Appendix is devoted to a detailed tabulation of the exact numerical values and best estimates for the critical temperatures, energies, specific heats, entropies, magnetizations, and the ferro‐ and antiferromagnetic susceptibilities of four plane lattices and the simple, body‐centered, and face‐centered cubic lattices.A square lattice gas with infinite nearest‐neighbor repulsions and weak second‐neighbor attractions (across alternate squares) is solved exactly for one particular temperature by transformation. The gas undergoes a transition at a density ρt=142, the corresponding form o...

M.A. Lasheen

Papers

The magnetic susceptibility and relaxation of a MnCl2.4H2O single crystal in the paramagnetic and antiferromagnetic states

The magnetic susceptibility and relaxation of MnCl2.4H2O powder in the antiferromagnetic and paramagnetic states