Effect of the Treatment under High-Temperature and High-Pressure on YNi2B2C Grain Boundary

Near critical temperature a negative peak in the field-cooled measured-upon-warming magnetization curve was observed in YNi2B2C superconductor, which was prepared by melting in an arc furnace then treated under high pressure. The study of effect of high-temperature and high-pressure treatment on the magnetization curves of bulk and powder samples measured at zero-field cooled and field cooled conditions shows that the negative magnetic peak in the field cooled magnetization comes from the grain boundary that leads a week link, but not from magnetic phase transition or the coexistence of superconductivity and magnetism. The result also demonstrates that the preparation and crystal growth of the material can be taken under high temperature and high pressure.