Effect of composition and pressure changes on the magnetic properties of Kondo lattices CeSi2−xGax

The variation of the magnetic properties as a function of the composition x was studied for the Kondo lattices CeSi2−xGax (0.1 ≤ x ≤ 1.3) with a structure of the α-ThSi2 type. It is established that the temperature of the transition from the paramagnetic state into the ferromagnetic state equals TM ≃ 10 K and is virtually independent of the gallium concentration in the interval 0.1 ≤ x ≤ 0.7. For compositions with x > 0.9, a sharp drop was observed in TM (x), and for x > 1.1 the compounds CeSi2−xGax are not magnetic. The effect of pressure P up to 16 kbar on the value TM was studied and the pressure derivative dTM/dP ≃ 0.13 K/kbar was determined for the compound CeSi1.3Ga0.7.