Phonon natures in Raman spectra of Y-Ba-Cu-O compounds

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.2003· OSTI ID:6910281

Zhang, M ^[1]; Yin, Z ^[2]; Hu, G; Chen, Q ^[3]

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1. Center for Materials Analysis and Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210008, China (CN)
2. Physics Department, Nanjing University, Nanjing 210008, (China)
3. Center for Materials Analysis, Nanjing University, Nanjing 210008, (China)

Raman spectra of the superconducting phase and nonsuperconducting phases, which mainly include semiconducting-phase and impurity-phase BaCuO{sub 2}, are examined in Y-Ba-Cu-O compounds. The doping effects from substitution of copper atoms by impurity atoms are discussed. The substitution of a lighter atom, e.g., vanadium, gives rise to local modes at 810 and 840 cm{sup {minus}1}, which are qualitatively elucidated by the theory of lattice dynamics in nonideal solids with a local perturbational operator related to the mass-defective coefficient. In tin substitution there is a critical doping {ital x}{sub {ital c}}=1. Above {ital x}{sub {ital c}} the system becomes nonsuperconducting, which could be explained on the basis of band-structure analysis. The emergence of a Raman line at 646 cm{sup {minus}1} below {ital T}{sub 0}=234 K shows a phase transition. The discrimination of this line from 640 cm{sup {minus}1} in impurity-phase BaCuO{sub 2} is clearly made.

• OSTI ID: 6910281
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:4; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
IMPURITIES
OXIDES
OXYGEN COMPOUNDS
PHONONS
QUASI PARTICLES
RAMAN SPECTRA
SPECTRA
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES