Free carriers density enhancement in the CuO2 planes of the YBa2Cu3O6Fy compounds at the insulator/metal transition: A Raman scattering analysis

Abstract Raman light scattering measurements have been performed on YBa 2 Cu 3 O 6 compounds doped with variable fluorine contents. The analysis of the phonon lineshape deformation related to the oxygens motion of the CuO 2 planes, have permitted us to show the increase of the free carriers density inside the CuO 2 planes with the fluorine doping and its enhancement at the Insulator/Metal transition.