Publication detail

Effective infrared reflectivity and dielectric function of polycrystalline alumina ceramics

NUZHNYY, D. PETZELT, J. BORODAVKA, F. VANĚK, P. ŠIMEK, D. TRUNEC, M. MACA, K.

Original Title

Effective infrared reflectivity and dielectric function of polycrystalline alumina ceramics

Type

journal article in Web of Science

Language

English

Original Abstract

Room-temperature infrared (IR) reflectivity, terahertz transmission and evaluated effective complex dielectric response of four polycrystalline alumina ceramics (corundum) with highly anisotropic grains in the IR range were determined. The spectra were compared with modelled spectra based on the known IR response of sapphire single crystal and Bruggeman and Lichtenecker models of the effective medium approximation (EMA). The results are extremely sensitive to the surface treatment (polishing), but do not depend on the grain size in the range of approximate to 0.3-1m and on the weak doping, needed for processing of optically transparent ceramics. As all the samples show similar grain shapes and topology, no measurable differences among the fully dense samples were observed. Agreement with the modelled spectra is reasonable, but shows a higher effective mode damping. A weak geometrical resonance was revealed near 500cm(-1), better described by the Bruggeman model. The small sample porosity up to 6.2% is revealed mainly as a reduced reflectivity above approximate to 650cm(-1), which produces weak losses in the high-frequency range above the TO phonon modes, better described by the Lichtenecker model.

Keywords

alumina, ceramics, effective dielectric function, effective medium approximation, geometrical resonances, infrared reflectivity

Authors

NUZHNYY, D.; PETZELT, J.; BORODAVKA, F.; VANĚK, P.; ŠIMEK, D.; TRUNEC, M.; MACA, K.

Released

1. 5. 2017

ISBN

0370-1972

Periodical

PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS

Year of study

254

Number

5

State

Federal Republic of Germany

Pages from

1

Pages to

8

Pages count

8

URL

https://onlinelibrary.wiley.com/doi/full/10.1002/pssb.201600607

BibTex

@article{BUT137370,
  author="Dimitry {Nuzhnyy} and Jan {Petzelt} and Fedir {Borodavka} and Přemysl {Vaněk} and Daniel {Šimek} and Martin {Trunec} and Karel {Maca}",
  title="Effective infrared reflectivity and dielectric function of polycrystalline alumina ceramics",
  journal="PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS",
  year="2017",
  volume="254",
  number="5",
  pages="1--8",
  doi="10.1002/pssb.201600607",
  issn="0370-1972",
  url="https://onlinelibrary.wiley.com/doi/full/10.1002/pssb.201600607"
}