Spin relaxation in Mn12-acetate

被引：80

作者：

Leuenberger, MN ^{[1
]}

Loss, D ^{[1
]}

机构：

[1] Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland

来源：

EUROPHYSICS LETTERS | 1999年 / 46卷 / 05期

关键词：

D O I：

10.1209/epl/i1999-00321-x

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present a comprehensive theory of the magnetization relaxation in a Mn-12-acetate crystal based on thermally assisted spin tunneling induced by quartic anisotropy and weak transverse magnetic fields. The overall relaxation rate as a function of the magnetic field is calculated and shown to agree well with data including all resonance peaks. The Lorentzian shape of the resonances is also in good agreement with recent data. A generalised master equation including resonances is derived and solved exactly. It is shown that many transition paths with comparable weight exist that contribute to the relaxation process. Previously unknown spin-phonon coupling constants are calculated explicitly.

引用

页码：692 / 698

页数：7

共 31 条

[1]

Abragam A., 1970, ELECT PARAMAGNETIC R

[2] MESOSCOPIC QUANTUM TUNNELING OF THE MAGNETIZATION [J].

BARBARA, B ;

WERNSDORFER, W ;

SAMPAIO, LC ;

PARK, JG ;

PAULSEN, C ;

NOVAK, MA ;

FERRE, R ;

MAILLY, D ;

SESSOLI, R ;

CANESCHI, A ;

HASSELBACH, K ;

BENOIT, A ;

THOMAS, L .

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1995, 140 :1825-1828

[3] High-frequency EPR spectra of a molecular nanomagnet: Understanding quantum tunneling of the magnetization [J].

Barra, AL ;

Gatteschi, D ;

Sessoli, R .

PHYSICAL REVIEW B, 1997, 56 (13) :8192-8198

[4]

Blum K., 1996, DENSITY MATRIX THEOR

[5]

CALLEN ER, 1965, PHYS REV A, V139, P455

[6]

DOHM V, 1975, Z PHYS B CON MAT, V21, P369, DOI 10.1007/BF01325397

[7] Resonant magnetic quantum tunneling through thermally activated states [J].

Fernández, JF ;

Bartolomé, J ;

Luis, F .

JOURNAL OF APPLIED PHYSICS, 1998, 83 (11) :6940-6942

[8] Mixed quantum-thermal relaxation in Mn12 acetate molecules [J].

Fort, A ;

Rettori, A ;

Villain, J ;

Gatteschi, D ;

Sessoli, R .

PHYSICAL REVIEW LETTERS, 1998, 80 (03) :612-615

[9] Macroscopic measurement of resonant magnetization tunneling in high-spin molecules [J].

Friedman, JR ;

Sarachik, MP ;

Tejada, J ;

Ziolo, R .

PHYSICAL REVIEW LETTERS, 1996, 76 (20) :3830-3833

[10] Resonant magnetization tunneling in Mn12 acetate:: The absence of inhomogeneous hyperfine broadening [J].

Friedman, JR ;

Sarachik, MP ;

Ziolo, R .

PHYSICAL REVIEW B, 1998, 58 (22) :14729-14732

← 1 2 3 4 →