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

Technical Report · Thu Apr 01 04:00:00 EST 1999

DOI:https://doi.org/10.2172/334199· OSTI ID:334199

McQueeney, R J; Sarrao, J L

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., 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
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
HOLES
INELASTIC SCATTERING
LANTHANUM OXIDES
NEUTRONS
NICKEL OXIDES
PHONONS
STOICHIOMETRY
STRONTIUM OXIDES