Anomalies in the Relaxation of Small Magnetic Particles at Very Low Temperatures
arXiv:cond-mat/9609025
Abstract
The magnetization relaxation rate of small gamma-Fe2O3 particles dispersed in a silica matrix has been measured from 60 mK to 5 K. It shows a minimum around 150 mK, that can be discussed in terms of either thermal or quantum relaxation regime.
8 pages, 4 figures