Temperature dependence of far-infrared difference reflectivity of YBa/sub 2/Cu/sub 3/O/sub 7-//sub y/

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.6716· OSTI ID:6317318

Krenn, H; Bauer, G; Vogl, G; Strasser, G; Gornik, E

Far-infrared difference reflectivity spectra (50--450 cm/sup -1/) below, across and above the transition temperature on polycrystalline single-phase YBa/sub 2/Cu/sub 3/O/sub 7-//sub y/ samples were measured. The data are compared with model fits using the explicit temperature dependence of the Mattis-Bardeen conductivity, an effective-medium approach and temperature-dependent phonon oscillator parameters and alternatively a plasma model. For the plasma model we alternatively use a generalized Drude-like expression with a frequency-dependent damping after Thomas et al. (Phys. Rev. B 36, 846 (1987)) or the original model with Orenstein et al. (Phys. Rev. B 36, 729 (1987)) and Sherwin, Richards, and Zettl (Phys. Rev. B 37, 1587 (1988)) with a Drude contribution plus a mid-infrared oscillator, but with constant carrier relaxation rates. The models explain the difference reflectivity data (precision <0.2%) with a fitting accuracy of 1--2 % (Mattis-Bardeen model) or 2--3 % (plasma model) over the full temperature range. In order to investigate their applicability, reflectivity, and conductivity data of a highly oriented YBa/sub 2/Cu/sub 3/O/sub 7-//sub y/ sample, as recently published by Bonn et al. (Phys. Rev. Lett. 58, 2249 (1987)), were also fitted with both models. Because of the frequency dependence of the free-carrier damping rates, it was important to fulfill the Kramers-Kronig relations between the real and the imaginary part of the dynamic conductivity in the calculations. For both models the characteristic dependences of the conductivity on frequency and temperature are given.

• Research Organization: Institut fuer Physik, Montanuniversitaet Leoben, A-8700 Leoben, Austria
• OSTI ID: 6317318
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 39:10
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
REFLECTIVITY
COPPER OXIDES
YTTRIUM OXIDES
ENERGY GAP
FAR INFRARED RADIATION
LOW TEMPERATURE
POLYCRYSTALS
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTALS
ELECTROMAGNETIC RADIATION
INFRARED RADIATION
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
&amp; Refractories- Physical Properties