5 research outputs found

    Doping evolution of the phonon density of states and electron-lattice interaction in Nd2x_{2-x}Cex_xCuO4+δ_{4+\delta}

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    We use inelastic neutron scattering to study the evolution of the generalized phonon density of states (GDOS) of the nn-type high-TcT_c superconductor Nd2x_{2-x}Cex_xCuO4+δ_{4+\delta} (NCCO), from the half-filled Mott-insulator (x=0x=0) to the Tc=24T_c=24 K superconductor (x=0.15x=0.15). Upon doping the CuO2_2 planes in Nd2_2CuO4+δ_{4+\delta} (NCO) with electrons by Ce substitution, the most significant change in the GDOS is the softening of the highest phonon branches associated with the Cu-O bond stretching and out-of-plane oxygen vibration modes. However, the softening occurs within the first few percent of Ce-doping and is not related to the electron doping induced nonsuperconducting-superconducting transition (NST) at x0.12x\approx 0.12. These results suggest that the electron-lattice coupling in the nn-type high-TcT_c superconductors is different from that in the pp-type materials.Comment: 4 pages and 3 figure
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