Eur. Phys. J. B (2013) 86: 62
https://doi.org/10.1140/epjb/e2012-30937-8

Regular Article

Resonant ultrasound spectroscopy – a tool to probe magneto-elastic properties of ferromagnetic shape memory alloys^*

¹ Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic
² Institute of Thermomechanics, Academy of Sciences of the Czech Republic, Dolejskova 5, 182 00 Prague 8, Czech Republic

^a e-mail: heczko@fzu.cz

Received: 12 October 2012
Received in final form: 5 December 2012
Published online: 20 February 2013

Abstract

Resonant ultrasound spectroscopy (RUS) was used to investigate the changes of elastic properties induced by magnetic field in magnetic shape memory alloys Ni-Mn-Ga and Co-Ni-Al. In contrast to large magneto-elastic response of Ni₂MnGa austenite, there is only very weak response of Co-Ni-Al. This indicates that the austenite phase of Ni-Mn-Ga can have a privileged position and this may be a reason for the existence of magnetic shape memory effect. In contrast to austenite, the magneto-elastic response in Ni-Mn-Ga martensite is very small with large damping due to existence of twin boundaries. The measurement showed that RUS can be a powerful method to probe magneto-elastic properties of shape memory alloys.