Magnetic characteristics of RNi4B compounds (R=Y, Pr, Sm, Tb, Ho and Er)

The magnetic properties of RNi4B compounds with R=Y, Pr, Sm, Tb, Ho and Er have been studied. These compounds crystallize in a hexagonal structure with the P6/mmm space group. YNi4B shows superconducting behavior below ∼12 K, while PrNi4B is paramagnetic but contains a contribution of a ferromagnetic impurity phase. For compounds with R=Sm, Tb, Ho and Er transitions to magnetically ordered state are visible at 38, 21, 6 and 12 K, respectively. A large hysteresis loop is observed for the SmNi4B compound with a coercive field HC>7.0 T, whereas the RNi4B compounds of the other rare earths are characterized by an HC lower than 0.06 T at 5 K