The effect of uniaxial pressure on the magnetic anisotropy of the Mn_{12}-Ac single-molecule magnet

TL;DR

This study investigates how applying uniaxial pressure along the easy axis of Mn_{12}-Ac affects its magnetic properties, revealing increased anisotropy and energy barrier, supported by experimental and theoretical results.

Contribution

It provides new insights into pressure-induced changes in magnetic anisotropy and energy barriers in single-molecule magnets, combining experimental and computational approaches.

Findings

Pressure increases the magnetic anisotropy constant D.

Quantum tunneling fields shift with applied pressure.

The energy barrier for magnetization reversal increases under pressure.

Abstract

We study the effect of uniaxial pressure on the magnetic hysteresis loops of the single-molecule magnet Mn_{12}-Ac. We find that the application of pressure along the easy axis increases the fields at which quantum tunneling of magnetization occurs. The observations are attributed to an increase in the molecule's magnetic anisotropy constant D of 0.142(1)%/kbar. The increase in D produces a small, but measurable increase in the effective energy barrier for magnetization reversal. Density-functional theory calculations also predict an increase in the barrier with applied pressure.