DETERMINATION OF CRYSTAL STRUCTURE AND CRYSTALLOGRAPHIC CHARACTERISTICS IN Ni-Mn-Ga FERROMAGNETIC SHAPE MEMORY ALLOYS

作者：Cong D Y^*; Zhang Y D; Esling C; Wang Y D; Zhao X; Zuo L

来源：International Journal of Modern Physics B, 2009, 23(6-7): 1771-1776.

DOI：10.1142/s0217979209061603

• Ferromagnetic shape memory alloys (FSMAs)
• crystal structure
• misorientation
• neutron diffraction
• electron backscattered diffraction (EBSD)

Ni-Mn-Ga ferromagnetic shape memory alloys (FSMAs) have received great attention during the past decade due to their giant magnetic shape memory effect and fast dynamic response. The crystal structure and crystallographic features of two Ni-Mn-Ga alloys were precisely determined in this study. Neutron diffraction measurements show that Ni(48)Mn(30)Ga(22) has a Heusler austenitic structure at room temperature; its crystal structure changes into a seven-layered martensitic structure when cooled to 243K. Ni(53)Mn(25)Ga(22) has an I4/mmm martensitic structure at room temperature. Electron backscattered diffraction (EBSD) analyses reveal that there are only two martensitic variants with a misorientation of similar to 82 degrees around (110) axis in each initial austenite grain in Ni(53)Mn(25)Ga(22). The investigation on crystal structure and crystallographic features will shed light on the development of high-performance FSMAs with optimal properties.

• 出版日期2009-3-20
• 单位东北大学