DE-HAAS-VAN-ALPHEN EFFECT AND MAGNETORESISTANCE IN FERROMAGNETIC RENI

The transverse magnetoresistance and de Haas-van Alphen (dHvA) effect in ferromagnetic RENi (RE: Pr, Nd and Sm) have been studied in fields up to 120 kOe and at temperatures down to 1.3 K. It was found that the Fermi surfaces of the three compounds contain an open surface along t he b axis as in a non magnetic LaNi. On the other hand, the c-directio nal open surface was not found in PrNi and NdNi, being different from LaNi. Many dHvA frequency branches with the frequencies range of 2MG t o 50MG were found. These branches show that the Fermi surfaces of thes e compounds are altered from that of LaNi by a relatively large spin s plitting of the conduction band.