Observation of an unusual equilibrium in the molecular nano-magnet Fe_8

Research paper by V. Villar, E. Lhotel, C. Sangregorio, C. Paulsen

Indexed on: 05 Aug '05Published on: 05 Aug '05Published in: Physics - Other


Magnetization measurements made in small fields as a function of temperature reveal an unusual equilibrium below 900 mK for the molecular nano-magnet Fe_8. Measurements of the relaxation of the magnetization demonstrate that the approach to the equilibrium is non-trivial and suggest that a competition exists between quantum tunneling of the giant spins and thermodynamic behavior. As a result, at very low temperature the entropy of the spin system remains very large.