Low loss alumina dielectrics by aqueous tape casting: The
influence of composition on the loss tangent

J 2012

Low loss alumina dielectrics by aqueous tape casting: The influence of composition on the loss tangent

CHOVANEC, Jozef; Dusan GALUSEK; Jozef RÁHEĽ a Pavol ŠAJGALÍK

Základní údaje

Originální název

Low loss alumina dielectrics by aqueous tape casting: The influence of composition on the loss tangent

Název česky

Nízkostrátové korundové dielektrikum připravené technikou tape casting: Vliv složení na strátový úhel

Autoři

CHOVANEC, Jozef; Dusan GALUSEK; Jozef RÁHEĽ a Pavol ŠAJGALÍK

Vydání

Ceramics International, Elsevier, 2012, 0272-8842

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

20504 Ceramics

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 1.789

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/12:00064286

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1016/j.ceramint.2012.01.020

UT WoS

000303634900031

Klíčová slova anglicky

Tape casting; Loss tangent; Alumina; Dopants

Štítky

AKR, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 10. 4. 2013 20:04, Ing. Andrea Mikešková

Anotace

V originále

Polycrystalline aluminas with various concentrations of oxide dopants CaO, MgO, and TiO2, ranging from 0.05 wt.% to 5 wt.% (3 wt.% in case of MgO), as well as pure alumina references were prepared by tape casting of aqueous suspensions and sintered in air at 1600 degrees C for 4 h for applications as low dielectric loss electroceramics. Loss tangents were measured at room temperature in the frequency range between 1 and 100 kHz as the key parameter for the intended application. The values of loss tangents of doped materials were influenced by the concentration of dopants. The addition of 0.5 and 5 wt.% of TiO2 and 3 wt.% of MgO decreased the value of loss tangent in the whole frequency range. The addition of these dopants eliminated abnormal grain growth and decreased the amount of residual porosity. By doing so, the dopants compensated the negative influence of process impurities and decreased the loss tangent values. The cations (Ti4+) with high solubility in the Al2O3 crystal lattice were preferably built into the grain boundary glass, thus efficiently reducing the concentration of polarizable defects in corundum matrix; the formation of vitreous phase had a positive effect on the value of loss tangent in TiO2 doped samples. The increased values of loss tangent were related to lower density of prepared materials, and the presence of residual porosity. Other contributing factors were especially the formation of calcium-containing secondary crystalline phases, and the increased concentration of lattice defects due to incorporation of atoms with different valencies to alumina crystal lattice. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Citovat

CHOVANEC, Jozef; Dusan GALUSEK; Jozef RÁHEĽ a Pavol ŠAJGALÍK. Low loss alumina dielectrics by aqueous tape casting: The influence of composition on the loss tangent. Ceramics International. Elsevier, 2012, roč. 38, č. 5, s. 3747-3755. ISSN 0272-8842. Dostupné z: https://doi.org/10.1016/j.ceramint.2012.01.020.

@article{1090574,
   author = {Chovanec, Jozef and Galusek, Dusan and Ráheľ, Jozef and Šajgalík, Pavol},
   article_number = {5},
   doi = {https://doi.org/10.1016/j.ceramint.2012.01.020},
   keywords = {Tape casting; Loss tangent; Alumina; Dopants},
   language = {eng},
   issn = {0272-8842},
   journal = {Ceramics International},
   title = {Low loss alumina dielectrics by aqueous tape casting: The influence of composition on the loss tangent},
   volume = {38},
   year = {2012}
}

TY  - JOUR
ID  - 1090574
AU  - Chovanec, Jozef - Galusek, Dusan - Ráheľ, Jozef - Šajgalík, Pavol
PY  - 2012
TI  - Low loss alumina dielectrics by aqueous tape casting: The influence of composition on the loss tangent
JF  - Ceramics International
VL  - 38
IS  - 5
SP  - 3747-3755
EP  - 3747-3755
PB  - Elsevier
SN  - 02728842
KW  - Tape casting
KW  - Loss tangent
KW  - Alumina
KW  - Dopants
N2  - Polycrystalline aluminas with various concentrations of oxide dopants CaO, MgO, and TiO2, ranging from 0.05 wt.% to 5 wt.% (3 wt.% in case of MgO), as well as pure alumina references were prepared by tape casting of aqueous suspensions and sintered in air at 1600 degrees C for 4 h for applications as low dielectric loss electroceramics. Loss tangents were measured at room temperature in the frequency range between 1 and 100 kHz as the key parameter for the intended application. The values of loss tangents of doped materials were influenced by the concentration of dopants. The addition of 0.5 and 5 wt.% of TiO2 and 3 wt.% of MgO decreased the value of loss tangent in the whole frequency range. The addition of these dopants eliminated abnormal grain growth and decreased the amount of residual porosity. By doing so, the dopants compensated the negative influence of process impurities and decreased the loss tangent values. The cations (Ti4+) with high solubility in the Al2O3 crystal lattice were preferably built into the grain boundary glass, thus efficiently reducing the concentration of polarizable defects in corundum matrix; the formation of vitreous phase had a positive effect on the value of loss tangent in TiO2 doped samples. The increased values of loss tangent were related to lower density of prepared materials, and the presence of residual porosity. Other contributing factors were especially the formation of calcium-containing secondary crystalline phases, and the increased concentration of lattice defects due to incorporation of atoms with different valencies to alumina crystal lattice. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
ER  -

CHOVANEC, Jozef; Dusan GALUSEK; Jozef RÁHEĽ a Pavol ŠAJGALÍK. Low loss alumina dielectrics by aqueous tape casting: The influence of composition on the loss tangent. \textit{Ceramics International}. Elsevier, 2012, roč.~38, č.~5, s.~3747-3755. ISSN~0272-8842. Dostupné z: https://doi.org/10.1016/j.ceramint.2012.01.020.

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