Micro-probed Raman scattering study of optic phonons in YBa2Cu3Ox and Bi-Sr-Ca-Cu-O

Micro-probed Raman scattering spectra of YBa2Cu3Ox and Bi-Sr-Ca-Cu-O have been observed as a function of temperature near the transition temperature T-c using both the as-grown and annealed samples. In YBa2Cu3Ox, the mode at 230 cm(-1) appears in the annealed sample. The scattering intensity of this mode decreases to 0, as the temperature decreases to T-c. In Bi-Sr-Ca-Cu-O, phonon modes in the as-grown sample increase their peak frequencies monotonically with decreasing temperature. On the other hand, in the annealed sample, the 120 cm(-1) mode indicates a small softening near T-c.