Order-disorder transition and Curie transition in Ni_(70)Fe_(30) nanoalloy

摘要

This letter addresses the issue of the order-disorder and Curie transitions in Ni_(70)Fe_(10) nanoalloy. The ordered phase is observed at room temperature while the disordered phase appears when the nanoalloy is heated up to 773 K. By means of mechanical spectroscopy, x-ray diffraction, and vibrating sample magnetometer measurements, the order-disorder and Curie transition temperatures of 20 nm Ni_(70)Fe_(30)) nanoalloy are determined to be 636 and 728 K, both lower than the corresponding values in the coarse-grained form. Moreover, the reduction in these two critical temperatures is consistent with the predictions of a thermodynamic analytical model.