INFLUENCE OF PR DOPING AND OXYGEN DEFICIENCY ON THE SCATTERING BEHAVIOR OF YBA2CU3O7 THIN-FILMS

A comparative study of the complex conductivity and the scattering beh avior of Pr-doped and oxygen deficient YBa2Cu3O7 thin films with varyi ng Pr or oxygen content is performed using terahertz coherent time-dom ain spectroscopy in combination with de-resistivity measurements. Both Pr doping and removal of oxygen decrease the hole concentration in th e CuO2 planes. The specific conductivity behavior measured from 300 to 8 K shows two phase transitions: the superconducting transition at th e critical temperature and a transition that can be explained by a sup pression of the spin wave (spinon) density below the spin gap temperat ure. The nearly identical scattering behavior observed for both types of doping is discussed in the framework of P.W. Anderson's theory.