Izvestiya of Saratov University.
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)


magnetic properties

EXACT SOLUTIONS OF THE ISING MODELS IN A MAGNETIC FIELD

Previously, the author solved the one-, two- and three-dimensional Ising models in the absence of an external magnetic field exactly. Additional convincing proofs for these solutions are given here. The exact solutions of the Ising models in a magnetic field are found. It is shown that the conventional methods of solving the Ising models are incorrect. Heat capacities and zero-field magnetic susceptibilities of the Ising models are calculated exactly for all dimensions (including the case of polonium) and a flaw in Onsager’s solution for heat capacity is detected.

Magnetic Properties of Textured NiFe(111) and NiFe(200) Films

Thickness dependencies (d м 20–370 nm) of the saturation magnetization 4πМ, the ferromagnetic resonance linewidth ΔH, the coercivity field Hc and the shape of hysteresis loops were investigated for Ni80Fe20 (NiFe) films with (200) texture. The thickness dependencies of magnetic parameters for NiFe(200) films were compared with the dependencies 4πМ(d), ΔH(d) and Hc(d) for NiFe(111) films with strong (111) texture and polycrystalline NiFe films.