ELECTRONIC STATES OF DOPED HOLES AND MAGNETIC-PROPERTIES IN LA2-XMXCUO4 (M = SR, BA)

The magnetic susceptibility-chi and resistivity-rho were examined in La2-xMxCuO4 (M = Sr, Ba). The T-dependent part chi(s) of chi below x congruent-to x(c) (x(c) = 0.15 and 0.18 for M = Ba and Sr) consists of a term arising from antiferromagnetically correlated Cu-spins chi(F)s (T), which is characterized by a broad peak at T(max). On the other hand, chi(s) above x = x(c) consists of chi(F)s (T) and a Curie term (C/T which is small but grows with increasing x. The superconducting transition temperature T(c) decreases rapidly with increasing x above x(c). The relation between T(c) and C can be explained in terms of the magnetic depairing due to local moments. T(max) and the g-value of the Cu-spins are almost constant above x congruent-to 0.2, although these are strongly x-dependent for x < 0.2. This fact suggests that holes doped over the concentration p congruent-to 0.2 go onto electronic states which differ large y in character from those below p congruent-to 0.2. It is also found that a significant change in the rho-T curve occurs at x congruent-to 0.2.