Magnetic hysteresis (MAH) or coercivity is typically small in Ni-Mn-Ga-based MSMAs. However, very recently the fellow and his collaborators showed that MAH can be enlarged by boron doping and heat treatment, without increasing significantly the mechanical hysteresis1. They further showed that this finding enables novel functionality of the MSMAs as the new material exhibits properties of permanent magnet and magnetic shape memory behavior simultaneously. Presented experimental example of the novel functionality was demagnetization of material by a very small force (referred to as “mechanically-induced demagnetization”). Another effect envisaged was the “mechanically-induced rotation of remanent magnetization”; they proposed that the remanent magnetization of MSMAs can be rotated by a small mechanical force (similar behavior as piezomaterials but with electric field replaced by magnetic field). The proposed effects were recently confirmed to be possible by Peng et al. [REF]

 

Fig. 1. Some of the proposed non-usual magneto-mechanical effects
Fig. 1. Some of the proposed non-usual magneto-mechanical effects related to large magnetic hysteresis of MSM alloys.

 

[1] L. Straka, A. Soroka, O. Heczko, H. Hänninen, A. Sozinov, Scripta Materialia 87 (2014) 25.
[2] Qi Peng, Junjie Huang, Mingxiang Chen, Qingping Sun, Scripta Materialia 127 (2017) 49.