Raman study of Twin Free YBa${}_2$Cu${}_3$O${}_{6.5}$ (Ortho-II) Single Crystals

M. N. Iliev, V. G. Hadjiev, S. Jandl +5

The polarized Raman scattering spectra from freshly cleaved $ab$, $ac$, and $bc$ surfaces of high quality twin free YBa${}_2$Cu${}_3$O${}_{6.5}$ (Ortho-II) single crystals ($T_c$=57.5 K…