On Ground State Tunneling in Mn${}_{12}$-Acetate

Abstract

We report Hall sensor measurements of the magnetic relaxation of Mn${}_{12}$-acetate as a function of magnetic field applied along the easy axis of magnetization for a series of closely-spaced temperatures between 0.24 K and 1.9 K. We map out a region in the $H-T$ plane where ground state tunneling is observed, a region where tunneling proceeds via thermally-assisted tunneling, and a crossover region where both participate in the relaxation. We observe the occasional absence of ground-state tunneling under conditions where one would expect it to be present, and suggest a resolution to the enigma.

5 pages including 4 figures. Minor revisions to clarify explanations

References in corpus (6)

• Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12
• Spin tunneling via dislocations in Mn-12 acetate crystals
• Dislocation-induced spin tunneling in Mn-12 acetate
• A Distribution of Tunnel Splittings in Mn${}_{12}$-Acetate
• Linewidth of single photon transitions in Mn${}_{12}$-acetate
• Abrupt Transition between Thermally-Activated Relaxation and Quantum Tunneling in a Molecular Magnet

Cited by in corpus (2)

• Semiconductive and Photoconductive Properties of the Single Molecule Magnets Mn${}_{12}$-Acetate and Fe${}_8$Br${}_8$
• More Evidence for a Distribution of Tunnel Splittings in Mn${}_{12}$-acetate