Isotopic and isomorphic substitution of YBa/sub 2/Cu/sub 3/O/sub 6/ and YBa/sub 2/Cu/sub 3/O/sub 7/: Far-infrared spectroscopy and assignment of phonons

Journal Article · Thu Dec 01 04:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.11382· OSTI ID:6619464

Crawford, M K; Farneth, W E; McCarron, III, E M; Bordia, R K

We report results of far-infrared spectroscopic measurements on a series of isotopically (/sup 18/O) exchanged and isomorphically substituted materials in the YBa/sub 2/Cu/sub 3/O/sub 6/ and YBa/sub 2/Cu/sub 3/O/sub 7/ families. Based upon these measurements, we propose assignments for phonons in both the YBa/sub 2/Cu/sub 3/O/sub 6/ semiconducting phase and the YBa/sub 2/Cu/sub 3/O/sub 7/ superconducting phase. In YBa/sub 2/Cu/sub 3//sup 18/O/sub 7/, the lowest-frequency phonon at 155 cm/sup -1/ is seen to shift approx.2% to lower frequency when compared to the /sup 16/O material, demonstrating the role of oxygen in this vibration (which we have previously assigned as a c-axis-directed Cu-O chain bending mode of B/sub 1//sub u/ symmetry). This transverse-optical branch may be important for phonon-mediated superconductivity in this material, as indicated in a recent theoretical treatment by Weber and Matthiess (Phys. Rev. B 37, 599 (1988)).

• Research Organization: E. I. du Pont de Nemours and Co., Inc., Central Research and Development Department, Experimental Station, Wilmington, Delaware 19898
• OSTI ID: 6619464
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:16; 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
ANISOTROPY
BARIUM COMPOUNDS
BARIUM OXIDES
BASIC INTERACTIONS
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
COUPLING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ENERGY GAP
EVEN-EVEN NUCLEI
FAR INFRARED RADIATION
INFRARED RADIATION
INTERACTIONS
ISOTOPES
LIGHT NUCLEI
MATERIALS
NUCLEI
OPTICAL PROPERTIES
OXIDES
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PHONONS
PHYSICAL PROPERTIES
QUASI PARTICLES
RADIATIONS
SEMICONDUCTOR MATERIALS
SPECTRAL REFLECTANCE
STABLE ISOTOPES
STOICHIOMETRY
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
UMKLAPP PROCESSES
YTTRIUM COMPOUNDS
YTTRIUM OXIDES