Raman spectroscopy on nonstoichiometric Gd123 thin films

Characteristic of Raman Spectra, Crystal Structure and Superconductivity of Fe-Doped GdBa₂Cu_3-xFe_xO_7-δ Systems

“…For the undoped sample Gd123, the five modes observed in this spectrum are almost normal Raman-active. The peaks are the Ba-A g mode at 117cm -l , Cu(2)-A g at 144cm -l , out-of phase O(2,3)-B 1g at 329cm -l , in-phase O(2,3)-A g at 448cm -l , and the apical O(4) mode at 508cm -1 , which is close to the results of Gd123 thin films reported by Kakeshita et.al [6]. All the frequencies are well known phonons recorded in the orthorhombic structure [7].…”

“…In addition to these modes, some additional peaks are also seen in the sample. For example, the two peaks are at 229 and 589cm -1 respectively, which can be regarded as the modes induced by oxygen deficiency in chain site from the previous Raman study on Gd123 thin films [6]. Carefully look over Fig.…”

Raman Study of Tb-doped YBCO and Ce-doped GdBCO

“…Following Ref. [29], the observed phonons at 326 cm À1 , 444 cm À1 , and 507 cm À1 are the modes of the superconducting phase GdBa 2 Cu 3 O 7Àd . These have been respectively assigned to the outof-phase O(2, 3), in-phase O(2, 3), and O(4) stretching modes.…”

“…According to Ref. [29], several phonon lines due to the Raman active A g symmetry modes were observed at 125 cm À1 (barium mode), 153 cm À1 (CuO 2 -plane copper in-phase mode), 334 cm À1 (CuO 2 -plane oxygen out-of-phase mode), 449 cm À1 (CuO 2 -plane oxygen in-phase mode), and 508 cm À1 (apical oxygen mode) for the GdBa 2 Cu 3 O 7Àd orthorhombic structure. Fig.…”