Magnetically induced martensite transition in freestanding epitaxial Ni-Mn-Ga films

作者：Heczko O^*; Thomas M; Niemann R; Schultz L; Faehler S

来源：Applied Physics Letters, 2009, 94(15): 152513.

DOI：10.1063/1.3117240

• epitaxial growth
• gallium alloys
• magnetic epitaxial layers
• magnetic transitions
• magnetisation
• manganese alloys
• martensitic transformations
• nickel alloys
• shape memory effects

The martensitic transformation in freestanding Ni-Mn-Ga films obtained by epitaxial growth on NaCl (001) is analyzed. A temperature-magnetic field phase diagram reveals that the martensitic phase, exhibiting a higher magnetization compared to austenite, is favored by an external field. A shift of martensite temperature of dT/dH=0.36 K/T is observed, in good agreement with the value expected from a Clausius-Clapeyron equation. The practicality and energy input for actuation using magnetically induced martensitic transition is compared with a magnetically induced reorientation of martensitic variants.

• 出版日期2009-4-13