ELECTRON RAMAN-SCATTERING IN YBA2CU3O6.5 CRYSTALS

A detailed study has been made of electron scattering of light by YBa2 Cu3O6.5 Single crystals with a sharp superconducting transition at T-c approximate to 53 K. In the superconducting state, the spectral densi ty of the electron continuum undergoes a restructuring at frequencies omega less than or similar to 250 cm(-1) in the (x'x' polarization), a nd a 2 Delta peak arises at omega approximate to 200 cm(-1). In crosse d polarizations (x'y') the spectrum has a low intensity, and it does n ot undergo any significant changes at temperatures below T-c, in contr ast with the spectrum of YBa2Cu3O7. (C) 1995 American Institute of Phy sics.