The temperature and field dependences of internal friction and Young´s modulus are studied using a high-resolution ultrasonic (90 kHz) technique in stoichiometric ferromagnetic Ni₂MnGa shape memory alloy close to the premartensitic transformation temperature, TPM, in the demagnetized state and under moderate fields. Several new effects observed like an apparent Young´s modulus softening close to TPM under moderate fields, instead of the hardening outside this range, as well as existing controversies in the apparent elastic and anelastic properties of Ni₂MnGa close to TPM are explained by microeddy and macroeddy current relaxations that to date have been disregarded.
Keywords: Ni–Mn–Ga; anelasticity; eddy currents; elasticity; premartensite.