Photoinduced phase transformation in Y-Ba-Cu-O ceramics

Investigations of the photoinduced phenomena in Y-Ba-Cu-O ceramics have bee n performed using time-resolved measurements of the photovoltage, photocurr ent, photoresistivity and optical second harmonic generation. A time delay shift between the non-linear optical response and photocurrent was revealed . Application of external magnetic fields of up to 1 T reads to an essentia l decrease of the second harmonic generation response. Different approaches for explaining the observed data are discussed.