PHOTOINDUCED ENHANCEMENT OF SUPERCONDUCTIVITY

The photoinduced enhancement of superconductivity in RBa2Cu3Ox (R = ra re earth or yttrium) and PryR1-yBa2Cu3Ox was explored through temperat ure-dependent resistivity, Hall coefficient and mobility, and x-ray di ffraction measurements. The increases in T(c) are enhanced near the me tal-insulator transition, although photoinduced changes always exist i n oxygen-deficient samples. Several explanations, including intergrain Josephson coupling, photoassisted oxygen ordering, and the trapping o f photogenerated electrons in oxygen vacancies, are discussed.