A scanning Hall probe imaging study of the field induced martensite-austenite phase transition in Ni50Mn34In16 alloy

作者：Sharma V K^*; Moore J D; Chattopadhyay M K; Morrison Kelly; Cohen L F; Roy S B

来源：Journal of Physics: Condensed Matter , 2010, 22(1): 016008.

DOI：10.1088/0953-8984/22/1/016008

The martensite to austenite phase transition in the off-stoichiometric Heusler alloy Ni50Mn34In16 can be induced both by temperature change and by application of a magnetic field. We have used scanning Hall probe imaging to study the magnetic field induced martensite-austenite phase transition. The study provides clear visual evidence of the coexistence of the martensite and austenite phases across this field induced transition in both increasing and decreasing magnetic fields. Clear evidence of thermomagnetic history effects associated with the martensite-austenite phase transition is also obtained. Quantitative analysis of the magnetic field dependence of the volume fraction of the austenite phase in Ni50Mn34In16 shows evidence of a nucleation and growth mechanism across the field induced martensite-austenite phase transition. The local M-H loops constructed from the Hall images indicate the presence of a landscape of the critical magnetic field ( for the field induced transition) distributed over the sample volume and thus confirm the disorder influenced nature of this first-order magnetic phase transition.

• 出版日期2010-1-13