Different structures of monoclinic martensitic phases in titanium nickelide

The detailed theoretical and experimental analysis has been undertaken to b ring to light the true structure of the monoclinic phase in titanium nickel ide (NiTi) Theoretical models for such a phase have been proposed to descri be the experimental data. In addition to the well-known B19' phase two more structures - new monoclinic M phase with Cm space group and triclinic phas e with P1 space group - have been produced and analyzed in detail. Diffract ion patterns have been obtained from different NiTi samples by using the ne utron diffractometer IVV2 at different temperatures. From the refinement by DBWS-9411 program all these neutron patterns have been decoded successfull y. The proposed new structures and stereotype B19' one agree with correspon dant experimental data and the agreement is quite good. (C) 2000 Elsevier S cience B.V. All rights reserved.