Lattice effects in the La$_{\rm 2-x}$Sr$_{\rm x}$CuO$_{\rm 4}$ compounds

摘要: Systematic Raman studies on several cuprates (YBa$_{\rm 2}$Cu$_{\rm 3}$O$_{\rm x}$, YBa$_{\rm 4}$O$_{\rm 8}$ or Bi$_{\rm 2}$Sr$_{\rm 2}$CaCu$_{\rm 2}$O$_{\rm 8}$) have shown that at optimal doping the compounds are edge of lattice instability; once this level is exceeded, by means applying external hydrostatic pressure, changes in transition temperature accompanied spectral modifications. There strong indications reduction T$_{\rm c}$ correlated with a separation into nanoscale phases, which involve oxygen atoms CuO$_{\rm 2}$ planes. In work, modifications spectra La$_{\rm 2-x}$Sr$_{\rm x}$CuO$_{\rm 4}$ compound presented, show spin charge ordering coupled distortions whole region.