Magnetic relaxation phenomena in a CuMn spin glass
Department of Materials Science, Uppsala University, Box 534, 751 21 Uppsala,
Corresponding author: a Kristian.Jonason@material.uu.se
Revised: 30 November 1998
Published online: 15 July 1999
Experiments on the temperature and time dependence of the response function and the field cooled magnetisation of a Cu(Mn) spin glass at temperatures below the zero field spin glass temperature are used to explore the non-equilibrium nature of the underlying spin configuration. The results imply that a certain spin configuration is imprinted on the system as the temperature is decreased at a constant cooling rate. The cooling rate governs the magnitude of the FC magnetisation (MFC(H,T)). Any intermittent halt at a constant temperature, Ti, imprints an extended spin configuration, a process that is reflected e.g. in a downward relaxation of MFC. On continued cooling at the same rate, the magnitude of MFC(T) remains at a lower level than that of a continuous cooling curve. These results are put into the context of the corresponding behaviour of the response function as observed in measurements of the relaxation of the zero field cooled magnetisation.
PACS: 75.40.Gb – Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.) / 75.50.Lk – Spin glasses and other random magnets
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999