Ni2MnAl Single Crystals for Magnetic Scattering Neutron Holography

Ni2MnAl phase has the B2 crystal structure when an alloy was prepared at the moderate cooling rate. However, the crystal structure of Ni2MnAl oders from the B2 structure to the L21 structure by annealing at lower temperature than approximately 773 K. Ni2MnAl with the L21 structure exhibits martensitic phase transformation and ferromagnetic phase transition with decreasing temperature. On the contrary, Ni2MnAl with high Al content with the B2 structure exhibit no martensitic transformation but antiferromagnetic transition. With further cooling, Ni2MnAl with the B2 structure exhibit transition from antiferromagnetic phase to spin glass phase. Ni2MnAl with the B2 structure is suitable for developing a method to measure spin state of solids. [DOI: 10.1380/ejssnt.2011.331]