Sal. Foulds et al., ELECTRON-BEAM-INDUCED VOLTAGE CONTRAST AND MODULATED OPTICAL REFLECTANCE STUDIES OF YBCO THIN-FILM RESONATORS, Superconductor science and technology, 11(4), 1998, pp. 378-382
Electron-beam-induced voltage contrast (EBIV) and modulated optical re
flectivity (MOR) have been used to study the electrical properties of
superconducting microwave resonators. The three resonators studied wer
e patterned YBa2Cu3O7-x (YBCO) films on MgO substrates. The YBCO films
consisted of a 200 mu m wide central track of 8 mm length separated f
rom the ground plane by 80 mu m. A qualitative correlation was observe
d between the EBIV and MOR signals observed throughout the central tra
ck of the resonator. The EBIV results were taken close to the supercon
ducting transition while the MOR data were obtained at room temperatur
e. Both techniques are dependent on the local electrical properties wh
ich in turn are governed to a large extent by the local oxygen content
within the superconductor. The correlation between the MOR technique
and the more established EBIV technique has shown MOR to be a useful i
nspection tool for superconducting devices, particularly as MOR is a c
ontactless room-temperature technique.