The use of the half cycle technique to examine hysteresis in Zr(FexCr1−x)2 (x=0.55 and 0.75)—H systems

In order to better understand the hysteresis phenomena in metal–hydrogen systems, tests were made on two intermetallic compounds using a new technique, the half-cycle technique. It was seen that the portion of the materials converted to the β phase (hydride) in the half cycle is then converted much easier the second time in the first part of a subsequent complete cycle. This can be explained in terms of the sample condition changes in the initial half cycle when a portion of the sample disintegrates into a fine powder. The new surface produced makes it easier for the hydrogen dissociation and hydride (metal) nucleation processes to take place, resulting in less energy dissipation. Therefore, the magnitude of the hysteresis is reduced when a half cycle is followed by a complete cycle.