© 2008 American Institute of Physics

Published in Journal of Applied Physics, Vol. 103 No. 7 (2008) at doi: 10.1063/1.2828599


The phase transitions and magnetoresistance in polycrystalline ferromagnetic Ni50Mn50−xInx (15 ≤ x ≤ 16.2) Heusler alloys were studied through ac susceptibility, magnetization, thermal expansion, and resistivity measurements in the temperature interval of 5–400 K. The temperatures of the martensitic transformations were found to be strongly dependent on In concentration and on the strength of the applied external magnetic field. We observed large magnetoresistance (MR) Δρ/ρo ≈ −80% for x = 16 at T ≈ 125 K and Δρ/ρo ≈ −56% for x = 15 at T ≈ 309 K for ΔH = 5 T. In addition to large MR, the Ni50Mn50−xInx system exhibits ferromagnetic shape-memory effect and a large magnetic entropy change. Hence this system has potential to be a multifunctional applied material.