The magnetic and electrical properties of some rare earth tetraborides

Abstract A study of the magnetic and electrical properties of some rare earth tetraborides (PrB 4 , SmB 4 , GdB 4 , TbB 4 , DyB 4 , HoB 4 , ErB 4 and YbB 4 ) was carried out on powders and single crystals prepared by the flux method. The tetraborides were found to be metallic. The only exceptions are PrB 4 which is ferromagnetic and YbB 4 where no magnetic ordering was found down to 0.34 K; they are antiferromagnetic at low temperatures. PrB 4 and ErB 4 have a strong anisotropy along the c axis from the susceptibility and magnetization measurements. ErB 4 is of special interest because at low temperature it is antiferromagnetic in a weak magnetic field but shows two successive magnetic transitions with increasing field, leading finally to a purely ferromagnetic structure.