Influence of Gd doping on magnetic behaviour in La0.67Sr0.33CoO3, La0.67Sr0.33MnO3

M similar to T curves and M similar to H curves of the systems La0.67Sr0.33CoO3, La0.67Sr0.33MnO3 (x = 0.00, 0.05, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.67) were studied by experiments. Experimental results show that the magnetic structure of La0.67-xGdxSr0.33CoO3 system exhibits the cluster glass state with doping Gd increasing. The M similar to T curves of samples x > 0.10 exhibit a peculiar phenomenon that M value rises sharply at low temperature range. The magnetic structure of La0.67-xGdxSr0.33MnO3 system changes from the long-rang ferromagnetic order to the cluster glass state, and anti-ferromagnetic state. The M similar to T curves of samples x >= 0.50 decline sharply at low temperature range. The different phenomena shown by the two systems come from different coupling function between Gd and Co, Mn and from spin state transition of Co.