Acoustic emission across the magnetostructural transition of the giant magnetocaloric Gd5Si2Ge2

We report on the existence of acoustic emission during the paramagnetic-monoclinic to ferromagnetic-orthorhombic magnetostructural phase transition in the giant magnetocaloric Gd5Si2Ge2 compound. The transition kinetics have been analyzed from the detected acoustic signals. It is shown that this transition proceeds by avalanches between metastable states.