Structural and Magnetic Properties of Magnetic Shape Memory Alloy Ni₄₆Mn₄₁In₁₃ under Magnetic Fields

抄録

The structural and magnetic properties of Heusler alloy Ni₄₆Mn₄₁In₁₃ were studied by magnetization and X-ray powder diffraction measurements in the 4.5–350 K temperature range and in magnetic fields up to 5 T. The alloy undergoes martensitic transformation from a L2₁-type cubic structure with a_c = 0.600 nm at 293 K to a six-layered monoclinic (6M) structure in the transition temperature of 160–230 K. The lattice parameters for the 6M structure were estimated to be a_m = 0.441 nm, b_m = 0.557 nm, c_m = 1.30 nm, α_m = 90.0°, β_m = 94.0°, and γ_m = 90.0° at 75 K. In this transformation from the L2₁ to 6M structures, the cell volume contracts by 0.34% at 8 K. In addition, we observed the magnetic field-induced reverse transformation of this alloy.