The effect of uniaxial pressure on the magnetic anisotropy of the Mn₁₂-Ac single-molecule magnet

¹ Department of Physics, Amherst College - Amherst, MA 01002, USA
² Department of Physics, University of Central Florida - Orlando, FL 32816, USA
³ Department of Physics, Virginia Tech - Blacksburg, VA 24061, USA
⁴ Department of Chemistry and Biochemistry, University of California at San Diego - La Jolla, CA 92093, USA
⁵ Department of Condensed Matter Physics, Weizmann Institute of Science - Rehovot 76100, Israel
⁶ Institute for Quantum Computing, University of Waterloo - Waterloo, Ontario, Canada, N2L 3G1

Received: 8 February 2013
Accepted: 15 May 2013

Abstract

We study the effect of uniaxial pressure on the magnetic hysteresis loops of the single-molecule magnet Mn₁₂-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.