“…We concluded from the concentration dependence of the transition that the observed metamagnetic transition is IEM inherent in YCo2 and roughly estimated the critical field B, of YCo2 to be about 100T. Similar but less sharp metamagnetic transitions were found in SC(CO,_,A~,)~ (Ishiyama and Endo 1987) and Lu(CO,-,A~,)~ (Sakakibara et a1 1987, Gabelko et a f 1987, Endo etaf 1988. In this paper, we have extended the measurement in Y(Col-,A1J2 up to about 100 T using a single-turn coil system in order to explore the transition for lower x.…”