Pressure Dependence of the Magnetic Anisotropy in the "Single-Molecule Magnet" [Mn4O3Br(OAc)3(dbm)3]

Abstract

The anisotropy splitting in the ground state of the single-molecule magnet [Mn4O3Br(OAc)3(dbm)3] is studied by inelastic neutron scattering as a function of hydrostatic pressure. This allows a tuning of the anisotropy and thus the energy barrier for slow magnetisation relaxation at low temperatures. The value of the negative axial anisotropy parameter $D_{\mathrm{cluster}}$ changes from -0.0627(1) meV at ambient to -0.0603(3) meV at 12 kbar pressure, and in the same pressure range the height of the energy barrier between up and down spins is reduced from 1.260(5) meV to 1.213(9) meV. Since the $\mathrm{Mn}-\mathrm{Br}$ bond is significantly softer and thus more compressible than the $\mathrm{Mn}-\mathrm{O}$ bonds, pressure induces a tilt of the single ion Mn${}^{3+}$ anisotropy axes, resulting in the net reduction of the axial cluster anisotropy.

arXiv comment4 pages, 3 figures

References in corpus (1)

• Low energy magnetic excitations of the Mn_{12}-acetate spin cluster observed by neutron scattering

Cited by in corpus (5)

• Landau-Zener tunneling in the presence of weak intermolecular interactions in a crystal of Mn4 single-molecule magnets
• Many-spin effects in inelastic neutron scattering and electron paramagnetic resonance of molecular nanomagnets
• Pressure dependence of the exchange interaction in the dimeric single-molecule magnet [Mn4O3Cl4(O2CEt)3(py)3]2 from inelastic neutron scattering
• Effects of uniaxial pressure on the quantum tunneling of magnetization in a high-symmetry Mn12 single-molecule magnet
• The effect of uniaxial pressure on the magnetic anisotropy of the Mn_{12}-Ac single-molecule magnet