Magnetoresistance and paramagnetic anomalies in La((2-x)/3)Ba((1+x)/3)Mn1-xCu(x)O(3) (x=0.2)

Magnetoresistance (MR) measurements for La(2-x)/3Ba(1+x)/3Mn1-xCuxO3 (x = 0 .2) show that the MR effect becomes observable at T-onset (similar to 200 K ), sharply increases on further cooling and reaches a maximum at T-c (simil ar to 105 K). Whereas paramagnetic (PM) resonance experiments reveal that P M anomalies occur just below T-onset. Above T-onset, the g-value keeps cons tant and the resonance linewidth Delta H-pp shows a linear temperature-depe ndent behaviour, while below T-onset, both the g-value and Delta H-pp anoma lously increase on cooling. It is interesting to find that at the range of T-c < T < T-onset, both g and Delta H-pp show temperature-dependent behavio urs similar to that for the MR against T. These findings suggest the same u nderlying physical origin for the MR effect and the PM anomalies.