Efective infrared reflectivity and dielectric function of polycrystalline alumina ceramics

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F17%3A00474911" target="_blank" >RIV/68378271:_____/17:00474911 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1002/pssb.201600607" target="_blank" >http://dx.doi.org/10.1002/pssb.201600607</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/pssb.201600607" target="_blank" >10.1002/pssb.201600607</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Efective infrared reflectivity and dielectric function of polycrystalline alumina ceramics

Popis výsledku v původním jazyce

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 ∼0.3–1 μm 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 500 cm−1, better described by the Bruggeman model. The small sample porosity up to 6.2% is revealed mainly as a reduced reflectivity above ∼650 cm−1, which produces weak losses in the high-frequency range above the TO phonon modes, better described by the Lichtenecker model.

Název v anglickém jazyce

Efective infrared reflectivity and dielectric function of polycrystalline alumina ceramics

Popis výsledku anglicky

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 ∼0.3–1 μm 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 500 cm−1, better described by the Bruggeman model. The small sample porosity up to 6.2% is revealed mainly as a reduced reflectivity above ∼650 cm−1, which produces weak losses in the high-frequency range above the TO phonon modes, better described by the Lichtenecker model.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/GA15-08389S" target="_blank" >GA15-08389S: Dielektrická a fononová spektroskopie multiferoik</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physica Status Solidi B-Basic Solid State Physics

ISSN

0370-1972

e-ISSN

—

Svazek periodika

254

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

8

Strana od-do

—

Kód UT WoS článku

000401149700011

EID výsledku v databázi Scopus

2-s2.0-85006371260