Magnetization-based assessment of correlation energy in canted Single-Chain Magnets

TL;DR

This paper introduces a numerical method to estimate correlation energy and exchange coupling in canted single-chain magnets using magnetization profiles, validated on manganese complexes, revealing linear decrease of correlation energy with field.

Contribution

It presents a novel approach to directly estimate correlation energy and exchange coupling from magnetization data in anisotropic single-chain magnets.

Findings

Correlation energy decreases linearly with magnetic field.

Method accurately estimates correlation energy and exchange coupling.

Identifies parameter regions with different magnetic behaviors.

Abstract

We demonstrate numerically that for the strongly anisotropic homometallic S=2 canted single-chain magnet described by the quantum antiferromagnetic Heisenberg model the correlation energy and exchange coupling constant can be directly estimated from the in-field-magnetization profile found along the properly selected crystallographic direction. In the parameter space defined by the spherical angles (\phi, \theta) determining the axes orientation, four regions are identified with different sequences of the characteristic field-dependent magnetization profiles representing the antiferromagnetic, metamagnetic and weak ferromagnetic type behavior. These sequences provide a criterion for the applicability of the anisotropic quantum Heisenberg model to a given experimental system. Our analysis shows that the correlation energy decreases linearly with field and vanishes for a given value H_{cr} which defines a special coordinates in the metamagnetic profile relevant for the zero-field correlation energy and magnetic coupling. For the single-chain magnet formed by the strongly anisotropic manganese(III) acetate meso-tetraphenylporphyrin complexes coupled to the phenylphosphinate ligands, the experimental metamagnetic-type magnetization curve in the c direction yields an accurate estimate of the values of correlation energy \Delta_{\xi}/k_B = 7.93 K and exchange coupling J/k_B=1.20 K.