Jinke Yu

Magnetostructural Transition in Heusler Mn-Ni-In Melt-Spun Ribbons

The magnetostructural transition of Heusler Mn-Ni-In melt-spun ribbons was investigated in the present work. Experimental results show that the characteristic temperatures of martensitic transformation enhance with substituting Mn with Ni for constant indium levels in Mn50-xNi40+xIn10 (at.%, x=0,2,4) melt-spun ribbons. Meanwhile, the ribbons evolve from the bcc cubic L21-type structured austenite to fourteen-layered modulated (14M) monoclinic martensite at room temperature. The martensitic transformation happens prior to the magnetic transition of austenite in Mn46Ni44In10 and lead to a sharp decrease of magnetization discrepancy across the martensitic transformation. It is beneficial for the magnetic enhancement to keep high Mn content.

Optical Floating-Zone Crystal Growth of Heusler Ni-Mn-Sn Alloy

Heusler Ni-Mn-Sn unidirectional crystal was fabricated using optical floating zone furnace in the present work. Higher static argon pressure up to 7 bar was employed to suppress the volatilization, and meanwhile, a titanium bar was preheated to remove residual oxygen in the furnace chamber prior to the formal crystal growth. Experimental results show that the obtained Ni50Mn37Sn13 unidirectional crystal was β{110} preferentially oriented at the rate of 6 mm/h. Magnetization curves measured along different directions under a low magnetic field of 100 Oe demonstrates strong anisotropy.