| Abstract: | By the use of x-ray crystallography and neutron diffraction we have determined the crystal structure of the  -and  -modifications of titanium doped NiMn. It is shown that the introduction of Ti does not change the structure of -NiMn, in which a B2 type of order is retained. The Ti atoms in this case lie predominantly in the Mn sublattice. In contrast, the titanium doping leads to a change in the stacking order of the close-packed layers in the low temperature -modification of NiMn. As the Ti content is increased from 0 to 15 at. % the stacking order changes from 3R to 4H via a series of intermediate long-period structures. It is proposed that the change in the crystal structure of -NiMn as Ti is introduced facilitates the appearance of the shape memory effect in this intermettalic compound.TsNIIchermet. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 114–122, January, 1994. |
