Magnetic properties of field annealed Ni-rich microwires

We report on the temperature evolution of the magnetic behavior of Ni-riched microwires obtained by the well-known Taylor-Ulitovsky method, with nominal compositions of Ni80Si6B14 and Ni78Si8B14, respectively. We study the Differential Scanning Calorimetry curves in the temperature range between RT to 600 °C, and the thermomagnetic evolution up to 800 °C at the two applied magnetic field values of 0.1 and 0.5 T for both, glass-coated microwires and uncovered microwires with the coating removed by selective etching in HF solution. We also correlate our measurements with magnetic domain pattern obtained by means of Bitter technique and RT VSM axial hysteresis loops. The evolutions of the magnetic and hysteresis properties for the as-quenched and annealed microwires are compared as a function of their thermo-magnetic history.