Relationship of Ferromagnetic Property with Porosity of Polycrystalline CaB_6 Ceramics

Polycrystalline Ca1+xB6(x = -0.02, 0, 0.02) ceramics were prepared by hot press and normal methods respectively and their ferromagnetic properties were analyzed systematically. The results indicate that all the samples prepared are ferromagnetic when sintering temperature is less than 1500 ℃. Though the porosity ratio of these samples prepared by these two methods is significant difference, the ferromagnetic properties are not changed with the changing porosity. We believe the ferromagnetism in the CaB6 ceramics is not concerned with the Ca vacancies or the porosity in the samples.