A possible explanation of meta-magnetic transition in CeRu2Si2 and magnetic behavior in Gd-poor (Ce-Gd)Ru2Si2

Aiming at getting any clue to the mechanism of characteristic behavior of meta-magnetic transition in CeRu2Si2 and the Ce 4f electronic states in Gd-poor contents, the (Ce-Gd)Ru2Si2 crystal mixed system was studied through magnetic measurements. A characteristic behavior of meta-magnetic transition observed in CeRu2Si2 was found to be reproduced in GdRu2Si2 in the temperature range between 30 K and 40 K. The meta-magnetic transition field was increased to higher field by the substitution of small amount of Gd contents of 0.01 and 0.02 at%. Furthermore, the reciprocal susceptibility in CeRu2Si2 (Gd=0) in temperature range between 15 K and 300 K revealed that the electronic state of Ce 4f was dominantly Ce3+, which was in accordance with a previous work, and the electronic states of Ce 4f in CeRu2Si2 could be described by the Van Vleck paramagnetic picture.