Modeling the Magnetic Properties and Mössbauer Spectra of Multifunctional Magnetic Materials Obtained by Insertion of a Spin-Crossover Fe(III) Complex into Bimetallic Oxalate-Based Ferromagnets

In this article, we present a theoretical microscopic approach to describe the magnetic and spectroscopic behavior of multifunctional hybrid materials which demonstrate spin crossover and ferromagnetic ordering. The low-spin to high-spin transition is considered as a cooperative phenomenon that is driven by the interaction of the electronic shells of the Fe ions with the full symmetric deformation of the local surrounding that is extended over the crystal lattice via the acoustic phonon field. The proposed model is applied to the analysis of the series [Fe(III)(sal2-trien)] [Mn(II)Cr(III)(ox)3]·solv, in short 1·solv, where solv = CH2Cl2, CH2Br2, and CHBr3.