The effect of hydrogen on the magnetic properties of quenched Ti-Zr-Ni rods

Ti-Zr-Ni quenched rods of 3, 2 and 1.5 mm diameter, prepared by vacuum-casting, were analyzed by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) before and after hydrogenation. Samples with two different compositions were prepared, i.e., Ti40Zr40Ni20 and Ti53Zr27Ni20. The as-cast rods were pulverized and hydrogenated from the gas-phase at 45 bar and 300 °C for 1000 min. The mass spectra of the desorbed hydrogen revealed the distribution of the hydrogen desorption temperatures from these alloys, whereas using thermogravimetry we obtained the mass% of desorbed H. We found that the ratio between the i-phase and the C14 Laves phase depends on the master alloy composition and the cooling rate, i.e., the rod diameter. VSM measurements revealed an about 30% decrease in paramagnetic susceptibility upon hydrogenation for all six investigated samples.