Evidence for strong electron-lattice coupling in La{sub 2-x}Sr{sub x}NiO{sub 4}

Journal Article · Wed Sep 01 00:00:00 EDT 1999 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.59627· OSTI ID:20216668

McQueeney, R J ^[1]; Sarrao, J S ^[2]

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1. Lujan Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

The inelastic neutron scattering spectra were measured for several Sr concentrations of polycrystalline La{sub 2-x}Sr{sub x}NiO{sub 4}. We find that the generalized phonon density-of-states is identical for x=0 and x=1/8. For x=1/3 and x=1/2, the band of phonons corresponding to the in-plane oxygen vibrations (>65 meV) splits into two subbands centered at 75 meV and 85 meV. The lower frequency band increases in amplitude for the x=1/2 sample, indicating that it is directly related to the hole concentration. These changes are associated with the coupling of oxygen vibrations to doped holes which reside in the NiO{sub 2} planes and are a signature of strong electron-lattice coupling. Comparison of La{sub 1.9}Sr{sub 0.1}CuO{sub 4} and La{sub 1.875}Sr{sub 0.125}NiO{sub 4} demonstrates that much stronger electron-lattice coupling occurs for particular modes in the cuprate for modest doping and is likely related to the metallic nature of the cuprate. (c) 1999 American Institute of Physics.

• OSTI ID: 20216668
• Journal Information: AIP Conference Proceedings, Vol. 483, Issue 1; Other Information: PBD: 1 Sep 1999; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
LANTHANUM OXIDES
STRONTIUM OXIDES
NICKEL OXIDES
NEUTRON DIFFRACTION
ELECTRON-PHONON COUPLING
LATTICE VIBRATIONS
EXPERIMENTAL DATA