title: Quantum nucleation in a single-chain magnet.
abstract: The field sweep rate (upsilon = dH/dt) and temperature (T) dependence of the magnetization reversal of a single-chain magnet is studied at low temperatures. As expected for a thermally activated process, the nucleation field (H(n)) increases with decreasing T and increasing upsilon. The set of H(n)(T,upsilon) data is analyzed with a model of thermally activated nucleation of magnetization reversal. Below 1 K, H(n) becomes temperature independent but remains strongly sweep rate dependent. In this temperature range, the reversal of the magnetization is induced by a quantum nucleation of a domain wall that then propagates due to the applied field.
authors.affiliation: Laboratoire L. Néel, associé à l'UJF, CNRS, BP 166, 38042 Grenoble Cedex 9, France.
authors.forename: W
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: R
authors.initials: R
authors.lastname: Clérac
authors.forename: C
authors.initials: C
authors.lastname: Coulon
authors.forename: L
authors.initials: L
authors.lastname: Lecren
authors.forename: H
authors.initials: H
authors.lastname: Miyasaka