A SPECTROSCOPIC ANISOTROPY ELLIPSOMETRY STUDY OF YBA2CU3O7-X SUPERCONDUCTORS

The effect of the optical anisotropy of the high temperature supercond ucting compound YB2Cu3O7-x (YBCO) on spectroscopic ellipsometry (SE) m easurements was studied. For this, the method of spectroscopic anisotr opy micro-ellipsometry (SAME) was employed on c-axis- as well as on a, b-axes-oriented YBCO single crystals. SAME measures the ellipsometric parameters Delta and Psi as a function of the angle alpha which descri bes sample rotation around the surface normal. The analysis of the res ulting Delta(alpha) and Psi(alpha)-curves yielded the ordinary and ave raged extraordinary complex refractive indices in the UV-VIS range. Ad ditionally, the crystallographic orientation angle phi between the opt ical axis and the surface normal could be determined. The single cryst al results were applied to SE measurements performed on differently or iented YBCO thin films which were prepared by ion beam sputter deposit ion on top of (100) SrTiO3 substrates. It is shown that SE allows for in-situ monitoring of the crystallographic orientation of thin YBCO fi lms. (C) 1998 Elsevier Science S.A.