Tracking spin-glass barriers versus field and temperature in a -Gd0.19 Si0.81

Detailed signatures of the states of the low-temperature spin-glass phase in a-GdSi films were followed using resistance fluctuations. Two-state switches between different spin-glass configurations were unambiguously identified by the field dependences of the occupation ratios of the states. The temperature dependences of the rates and occupation ratios were tracked in order to determine thermodynamic parameters of the switchers and the temperature dependences of barriers. A reasonable distribution of energy and entropy differences between states was found. Most importantly, the kinetic barriers were found to show no sign of divergence with lowering temperature, contrary to expectations based on prior theoretical and experimental works.