Martensitic transformations and mobility of twin boundaries in Ni_2MnGa alloys studied by using internal friction

摘要

Internal friction (IF) was measured in two non-stoichiometric Ni_2MnGa alloys. Several IF peaks attributed to some restructuring of the martensitic lattice were observed below M_s. From the strain dependence of IF, the activation enthalpy for movement of twin boundaries between martensitic domains was estimated to be equal to 0.02-0.04 eV.