Low-frequency internal friction in Cr75Fe16Mn9

The low-frequency internal friction in Cr75Fe16Mn9 allay has been measured in temperature range of 100-600 K and at frequencies lower than 10 Hz. It i s found that an internal fraction peak at 450 K and corresponding jump of m odules exist in the paramagnetic phase. This indicates there is a disorder- order transition on coupling states between individual spins for the Cr and Fe components. There is abroad internal friction peak in the temperature r ange from 200 to 300 K, which consists of a peak at 280 K and the extended broad peak at 220-270 K. We suggest that this effect is the reflection of t he spin density wave antiferromagnetic transition and the coexistence of di fferent magnetic phases in the alloy. Our results reflect the fact that int ernal friction method would be a sensitive and effective probe for investig ating the change of microstructure including electric structure.