We performed high resolution diffraction and inelastic neutron scattering measurements of Mn12- acetate. Using a very high energy resolution, we could separate the energy levels corresponding to the splitting of the lowest S multiplet. Data were analyzed within a single spin model (S=10 ground state), using a spin Hamiltonian with parameters up to 4th order. The non regular spacing of the transition energies unambiguously shows the presence of high order terms in the anisotropy (D= -0.457(2) cm−1, B0 4= -2.33(4) 10−5cm−1). The relative intensity of the lowest energy peaks is very sensitive to the small transverse term, supposed to be mainly responsible for quantum tunneling. This allows an accurate determination of this term in zero magnetic field (B4 4=±3.0(5) 10−5 cm−1). The neutron results are discussed in view of recent experiments and theories.
Low-energy magnetic excitations of the Mn-12-acetate spin cluster observed by neutron scattering / Mirebeau I; Hennion M; Casalta H; Andres H; Gudel HU; Irodova AV; Caneschi A. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - STAMPA. - 83:(1999), pp. 628-631.
Low-energy magnetic excitations of the Mn-12-acetate spin cluster observed by neutron scattering
CANESCHI, ANDREA
1999
Abstract
We performed high resolution diffraction and inelastic neutron scattering measurements of Mn12- acetate. Using a very high energy resolution, we could separate the energy levels corresponding to the splitting of the lowest S multiplet. Data were analyzed within a single spin model (S=10 ground state), using a spin Hamiltonian with parameters up to 4th order. The non regular spacing of the transition energies unambiguously shows the presence of high order terms in the anisotropy (D= -0.457(2) cm−1, B0 4= -2.33(4) 10−5cm−1). The relative intensity of the lowest energy peaks is very sensitive to the small transverse term, supposed to be mainly responsible for quantum tunneling. This allows an accurate determination of this term in zero magnetic field (B4 4=±3.0(5) 10−5 cm−1). The neutron results are discussed in view of recent experiments and theories.File | Dimensione | Formato | |
---|---|---|---|
PRL_1999.pdf
Accesso chiuso
Tipologia:
Versione finale referata (Postprint, Accepted manuscript)
Licenza:
Tutti i diritti riservati
Dimensione
269.03 kB
Formato
Adobe PDF
|
269.03 kB | Adobe PDF | Richiedi una copia |
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.