Crystal Growth and Magnetic Susceptibilities of Samarium and Europium Gallium Garnets

Single crystals of EuGaG and SmGaG were grown by the flux method and the magnetic susceptibilities measured between 2° and 300°K. The magnetic susceptibility of Eu3+ in EuGaG follows Van Vleck's formula for the free ion to a first approximation, due to the fact that any splitting δ of the J=1 levels produces an increase in the susceptibility of Eu3+ at low temperatures which is only second order in δ/hv(1; 0). In the case of SmGaG, the magnetic susceptibility at 4.2°K is reduced to ∼0.3 of the free ion value, indicating a strongly rhombic crystalline field.