Magnetic excitations in a Ni 4 magnetic molecule were investigated by inelastic neutron scattering and bulk susceptibility (χ bulk) techniques. The magnetic excitation spectrum obtained from the inelastic neutron scattering experiments exhibits three modes at energy transfers of ω=0.5, 1.35, and 1.6 meV. We show that the energy, momentum, and temperature dependencies of the inelastic neutron scattering data and χ bulk can be well reproduced by an effective spin Hamiltonian consisting of intramolecule exchange interactions, a single-ionic anisotropy, biquadratic interactions, and a Zeeman term. Under hydrostatic pressure, the bulk magnetization decreases with increasing pressure, which along with the biquadratic term indicates spin-lattice coupling present in this system.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2012 8 16|
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