Detailed electrical resistivity measurements for different twin configurations and crystallographic directions on Ni49Mn29Ga22 Heusler alloy were presented. Important results of these measurements were (i) the resistivity of the crystal was not related to the number of twin boundaries present (as previously reported) but instead depended upon the local environment of the atoms (c|| long direction or c long direction) in the crystal. The crystallographic anisotropy of the resistivity was appreciable. The intermartensitic transition temperature was strongly affected by the twin configuration and suppressed for the twinned state as compared to the single-variant states.

Effect of Twin Boundaries on Electrical Transport in a Ni–Mn–Ga Single Crystal. V.K.Srivastava, R.Chatterjee, R.C.O’Handley: Applied Physics Letters, 2006, 89[22], 222107 (3pp)