Phase diagram of a ferromagnetic semiconductor. The origin of superparamagnetism

Abstract

We study the theoretical model of a ferromagnetic semiconductor as a system of randomly distributed Ising spins with a long-range exchange interaction. Using the density-of-states approach, we analytically obtain the magnetic susceptibility and heat capacity over a wide range of temperatures and magnetic fields. It is shown that the finite system of spins in magnetic field less than a certain critical field is in a superparamagnetic state due to thermodynamic fluctuations. The complex phase structure of a ferromagnetic semiconductor is discussed.

References in corpus (4)

• Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO${}_2$
• Onset of ferromagnetism in low-doped GaMnAs
• Interplay between localization and magnetism in (Ga,Mn)As and (In,Mn)As
• Analytical solutions for Ising models on high dimensional lattices

Cited by in corpus (2)

• Optimal parallelisation strategies for flat histogram Monte Carlo sampling
• The Accuracy and Performance Analysis of the 1/t Wang-Landau Algorithm in the Joint Density of States Estimation