HALL-COEFFICIENT AND OXYGEN DEFICIENCY IN BAPB0.7BI0.3O3 SINGLE-CRYSTAL THIN-FILMS

The Hall coefficient and resistivity of single-crystal thin films of BaPb0.7Bi0.3O3-delta are measured for various numbers of oxygen vacancies incorporated by successive oxygen reduction treatments. It is found that increasing the number of oxygen vacancies in this system causes a significant increase in resistivity and an abrupt depression of T(c). The Hall coefficient decreases with increasing number of oxygen vacancies, reflecting a significant decrease in the carrier density. These changes are also accompanied by a noticeable decrease in the Hall mobility. It is also found that the depression of T(c) is proportional to the decrease in the Hall carrier density, showing a linear relationship between T(c) and the carrier density. The effects of oxygen vacancies on the transport properties in conducting oxides are discussed in relation to the high-T(c) cuprates.