Abstract
Raman spectrum changes resulting from different variations of the crystal lattice YBa 2Cu 3O δ (such as the substitutions Y → rare-earth element R, Ba → Sr, δ = 6 → δ = 7) have been studied. The concentration associated shift of vibrational frequencies of the oxygen atoms located in different layers of the lattice is shown to obey a general law: certain vibrations soften whereas the others harden. This vibrational behaviour is explained by the wave-like reconstruction of the crystal lattice (123). For the whole superconductor family RBa 2Cu 3O 7 and for YBa 2Cu 3O 7 at hydrostatis pressure the increase in T c with increasing frequency of the highest frequency A g-vibration is established. The results show the essential role of phonons in the high- T c superconductivity mechanism.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
