Difference between the cleaved surface and the polished surface on the Raman spectra of La$_{2-x}$Sr$_x$CuO$_4$

Sugai, S.; Takayanagi, Y.; Hayamizu, N.

Difference between the cleaved surface and the polished surface on the Raman spectra of La$_{2-x}$Sr$_x$CuO$_4$

Authors

Sugai, S.

Takayanagi, Y.

Hayamizu, N.

Description

The Raman spectra on the cleaved surface of La$_{2-x}$Sr$_x$CuO$_4$ is found to be different from those on the mechanically polished or chemically etched surface. On the cleaved surface, the step-like increase of the scattering intensity below 700 cm$^{-1}$ is washed away and the two-phonon peaks are preserved clearly even at the optimum doping. The difference is demonstrated on the optimally doped crystal at x=0.15 and the stripe phase crystal at x=0.115. The stripe phase is stabilized by defects induced by mechanical polishing.
9 pages, 4 figures