Achievement of large magnetostriction in [001]-textured Mn1-xNixCoSi/epoxy composites at room temperature

As a new kind of high-magnetostriction alloy, MnCoSi shows large magnetostriction during a metamagnetic transition. However, this alloy suffers from low strength, which is caused by the cracks generated from a martensitic transformation during cooling. In this paper, we will report that curing the mixture of MnCoSi-based powders and epoxy under a magnetic field is a promising method to enhance the strength and, meanwhile, maintain good magnetostrictive property. The MnCoSi-based powders used here have a low content of Ni, which can sharply reduce the critical field needed to drive the metamagnetic transition and tune the metamagnetic transition to be second-order. Profited from this improvement, [001]-textured Mn1-xNixCoSi/epoxy composites with enhanced strength and reversible magnetostriction are produced under a magnetic field of 1 T. The obtained magnetostriction is comparable to that of famous Terfenol-D and Fe-Ga alloys. Besides, the factors that can influence the texture and magnetostriction are discussed here.