Pressure-Induced Enhancement of the Magnetic Anisotropy in Mn(N(CN)$_{2}$)$_{2}$

TL;DR

This study investigates how applying pressure up to 12 kbar enhances magnetic transition temperature and anisotropy in Mn(N(CN)$_{2}$)$_{2}$, revealing pressure-induced changes in magnetic behavior and superexchange interactions.

Contribution

It provides new insights into pressure-induced enhancement of magnetic anisotropy and transition temperature in a 3D antiferromagnetic coordination polymer.

Findings

$T_c$ increases from 16.0 K to 23.5 K under pressure.

Magnetic behavior differences invert above 7.1 kbar.

Minor hysteresis loops appear above 8.6 kbar.

Abstract

Using dc and ac magnetometry, the pressure dependence of the magnetization of the three-dimensional antiferromagnetic coordination polymer Mn(N(CN)$_{2}$)$_{2}$ was studied up to 12 kbar and down to 8K. The magnetic transition temperature, $T_c$, increases dramatically with applied pressure $(P)$, where a change from $T_c(P=\text{ambient}) = 16.0$ K to $T_c(P=12.1$~kbar$) = 23.5$ K was observed. In addition, a marked difference in the magnetic behavior is observed above and below 7.1 kbar. Specifically, for $P<7.1$ kbar, the differences between the field-cooled and zero-field-cooled (fc-zfc) magnetizations, the coercive field, and the remanent magnetization decrease with increasing pressure. However, for $P>7.1$ kbar, the behavior is inverted. Additionally, for $P>8.6$ kbar, minor hysteresis loops are observed. All of these effects are evidence of the increase of the superexchange interaction and the appearance of an enhanced exchange anisotropy with applied pressure.