Mössbauer study of very dilute Pd(Fe) alloys at very low temperatures

The magnetic behaviour of very dilute (7 ppm and 0.6 ppm) Pd(Fe) alloys has been studied by Mössbauer spectroscopy in external fields up to 6 T in the temperature range between 0.018 and 300 K. No magnetic ordering was observed even at the lowest temperature. Above 0.067 K the magnetization exhibits free-spin behaviour. The saturation moment was found to be independent of temperature. Magnetic hyperfine patterns observed below 0.067 K were interpreted in terms of paramagnetic hyperfine interactions in the regime of slow electronic relaxation.