Evidence for strong electron-lattice coupling in La{sub 2{minus}x}Sr{sub x}NiO{sub 4}
The inelastic neutron scattering spectra were measured for several Sr concentrations of polycrystalline La{sub 2{minus}x}Sr{sub x}NiO{sub 4}. The authors 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.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 334199
- Report Number(s):
- LA-UR-99-644; CONF-990116-; ON: DE99002183; TRN: 99:004971
- Resource Relation:
- Conference: High temperature superconductivity conference, Miami, FL (United States), 7-13 Jan 1999; Other Information: PBD: [1999]
- Country of Publication:
- United States
- Language:
- English
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