Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog

Details Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog

2003-07-11

arxiv.org/abs/cond-mat/0307263v2

Physical Review B68, 214516 (2003)

Physics

Condensed Matter

Superconductivity

14 pages, 7 figures, Phys. Rev. B (in press). Minor changes + two figures removed as requested by referee

Scientific paper

10.1103/PhysRevB.68.214516

Neutron scattering has been used to investigate the crystal structure and lattice dynamics of superconducting Na0.3CoO2 1.4(H/D)2O, and the parent Na0.3CoO2 material. The structure of Na0.3CoO2 consists of alternate layers of CoO2 and Na and is the same as the structure at higher Na concentrations. For the superconductor, the water forms two additional layers between the Na and CoO2, increasing the c-axis lattice parameter of the hexagonal P63/mmc space group from 11.16 A to 19.5 A. The Na ions are found to occupy a different configuration from the parent compound, while the water forms a structure that replicates the structure of ice. Both types of sites are only partially occupied. The CoO2 layer in these structures is robust, on the other hand, and we find a strong inverse correlation between the CoO2 layer thickness and the superconducting transition temperature (TC increases with decreasing thickness). The phonon density-of-states for Na0.3CoO2 exhibits distinct acoustic and optic bands, with a high-energy cutoff of ~100 meV. The lattice dynamical scattering for the superconductor is dominated by the hydrogen modes, with librational and bending modes that are quite similar to ice, supporting the structural model that the water intercalates and forms ice-like layers in the superconductor.

Affiliated with

Also associated with

No associations

Rating

Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-628655