Composition-dependent crystal structure and martensitic transformation in Heusler Ni-Mn-Sn alloys
Document Type
Article
Publication Date
7-1-2013
Abstract
In the present work, modulated four- and five-layered orthorhombic, seven-layered monoclinic (4O, 10M and 14M) and unmodulated double tetragonal (L10) martensites are characterized in Heusler Ni-Mn-Sn alloys using X-ray diffraction, high-resolution transmission electron microscopy, electron diffraction techniques and thermal analysis. All modulated layered martensites exhibit twins and stacking faults, while the L10 martensite shows fewer structural defects. The substitution of Sn with Mn in Ni 50Mn37+xSn13-x (x = 0, 2, 4) enhances the martensitic transition temperatures, while the transition temperatures decrease with increasing Mn content for constant Sn levels in Ni50-yMn37+ySn13 (y = 0, 2, 4). The compositional dependence of the martensitic transition temperatures is mainly attributed to the valence electron concentration (e/a) and the unit-cell volume of the high-temperature phase. With increasing transition temperatures (or e/a), the resultant martensitic crystal structure evolves in a sequence of 4O ? 10M ? 14M ? L10 in bulk Ni-Mn-Sn alloys. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Recommended Citation
Zheng, Hongxing; Wang, Wu; Xue, Sichuang; Zhai, Qijie; Frenzel, Jan; and Luo, Zhiping, "Composition-dependent crystal structure and martensitic transformation in Heusler Ni-Mn-Sn alloys" (2013). College of Health, Science, and Technology. 785.
https://digitalcommons.uncfsu.edu/college_health_science_technology/785