POSITRON-ANNIHILATION STUDY OF Y1-XPRXBA2CU3O7

A positron annihilation study of Y1-xPrxBa2Cu3O7 was performed. The re sults showed that charge transfer between the CuO2 planes and 1D CuO c hains upon Pr doping, as proposed in the Literature, did not occur. Pr doping suppressed the anomaly of positron annihilation lifetime near and below T-c which has been observed in YBa2Cu3O7. The perfection of the 1D CuO chains was reduced by Pr doping and this may be partly resp onsible for the increase of resistivity with Pr doping, and finally th e semiconducting behaviour of DC resistivity in Y1-xPrxBa2Cu3O7 with x > 0.6.