Tailoring of magnetic properties of Heusler-type glass-coated microwires by annealing

As-prepared and annealed Heusler-type NiMnGa glass-covered microwires present considerable dependence of magnetization on magnetic field values attributed to the magnetic and atomic disorder. We observed that annealing conditions strongly affect structure, temperature dependence of magnetization and Curie temperature of microwires. After annealing a magnetic phase transition is observed at about 270-300 K which is beneficial for magnetic solid state refrigeration. Exchange bias effect, enhanced coercivity values at low temperature and features that can be attributed to coexistence of two magnetic phases are observed after long annealing of NiMnGa glass-covered microwires. (C) 2017 Elsevier B.V. All rights reserved.