Abstract
The Mossbauer effect, which is able to distinguish between isolated and clustered iron atoms, has been used to monitor the long term ( approximately 108s) effects of aging CuFe alloys at room temperature. The results are consistent with the movement of iron atoms by a vacancy mechanism of temperature independent (300-1350K) activation energy Qc=1.0 eV. The development of nonequilibrium gamma Fe has been monitored by tracing the dynamic changes which occurred over approximately 105s in spectra obtained directly on a 0.89% Fe specimen aged at 400 degrees C.