Superconducting properties and phonon spectra of Bi2Sr2Y1−xCaxCu2Oy

Infrared studies of the Bi cuprates

“…Following [11] and [13] the mode observed at about 95 cm −1 in phase 2212 originate from (BiO) 2 layers. This The next mode observed in phase 2212 at about 157 cm −1 has been assigned as an Sr-CuO(1) vibration [11,13,14]. In phase 2201 and 2223 the corresponding mode is observed at 155 cm −1 and 161 cm −1 respectively.…”

“…The mode at about 200 cm −1 in phase 2212 can originate from an Sr-O(1) layer [13]. In phase 2201 this mode was observed at 202 cm −1 and in phase 2223 at 197 cm −1 .…”

“…Referring to the calculated IR-active modes [11] and to [12][13][14] a tentative mode assignment is carried out for all three phases 2201, 2212 and 2223. The room-temperature IR-active modes obtained using Kramers-Kronig analysis of the reflectivity spectra are summarized in table 2.…”

“…Piro et al [12] have reported the room-temperature infrared reflectivity studies of 2212 phase. In [13,14] In this paper we report on the complete reflectivity measurements from 25 to 8000 cm −1 above and below the transition temperature in Bi 2223) superconductors. We analyse the temperature-and frequency-dependent far-infrared part of the spectrum.…”

Micro-Raman study of polycrystalline Bi2Sr2Ca1-xErxCu2O8+δ (0.0x1.0) composition

“…The fact that the wavenumber is independent of Er concentration suggests non-involvement of Ca or Er atoms in these vibrations. Following Yoshizaki et al 16 and Prade et al,2 the 318 cm~1 band may be assigned to the BiÈO(2), O(3) stretching vibrations. The band at 285 cm~1 may be identiÐed with the out-of-phase angle bending mode of oxygen in CuÈO layers as report-B 1g ed by Cardona et al 9 The peaks observed at 465 and 645 cm~1 are noteworthy.…”