Effect of Al2O3 on the structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3

G. A. Ravi; F. Azough; R. Freer

doi:10.1016/j.jeurceramsoc.2006.11.010

Effect of Al2O3 on the structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3

G. A. Ravi, F. Azough, R. Freer

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

The effect of excess Al2O3 on the densification, structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3 (CTLA) was investigated. CTLA ceramics were prepared using the conventional mixed oxide route. Excess Al2O3 in the range of 0.1-0.5 wt% was added. It was found that Al2O3 improved the densification. A phase rich in Ca and Al was found in the microstructure of Al2O3 doped samples. Additions of Al2O3 coupled with the slow cooling after sintering improved the microwave dielectric properties. CTLA ceramics with 0.25 wt% Al2O3 cooled at 5 °C/h showed high density and a uniform grain structure with εr = 46, Q × f = 38,289 and τf = +12 ppm/°C at 4 GHz. XRD and TEM examinations showed the presence of (1 1 2) and (1 1 0) type twins arising from a-a-c+ tilt system with the presence of anti-phase domain boundaries from the displacement of A-site cations of the orthorhombic perovskite structure. © 2006 Elsevier Ltd. All rights reserved.

Original language	English
Title of host publication	Journal of the European Ceramic Society\|J. Eur. Ceram. Soc.
Publisher	Elsevier BV
Pages	2855-2859
Number of pages	4
Volume	27
DOIs	https://doi.org/10.1016/j.jeurceramsoc.2006.11.010
Publication status	Published - 2007
Event	4th International Conference on Microwave Materials and Their Applications (MMA2006) - Oulu, FINLAND Duration: 12 Jun 2006 → 15 Jun 2006

Conference

Conference	4th International Conference on Microwave Materials and Their Applications (MMA2006)
City	Oulu, FINLAND
Period	12/06/06 → 15/06/06

Keywords

Microwave dielectrics

Access to Document

10.1016/j.jeurceramsoc.2006.11.010

Cite this

@inproceedings{cec7c66d0b874e69836efbcef57c7521,

title = "Effect of Al2O3 on the structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3",

abstract = "The effect of excess Al2O3 on the densification, structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3 (CTLA) was investigated. CTLA ceramics were prepared using the conventional mixed oxide route. Excess Al2O3 in the range of 0.1-0.5 wt% was added. It was found that Al2O3 improved the densification. A phase rich in Ca and Al was found in the microstructure of Al2O3 doped samples. Additions of Al2O3 coupled with the slow cooling after sintering improved the microwave dielectric properties. CTLA ceramics with 0.25 wt% Al2O3 cooled at 5 °C/h showed high density and a uniform grain structure with εr = 46, Q × f = 38,289 and τf = +12 ppm/°C at 4 GHz. XRD and TEM examinations showed the presence of (1 1 2) and (1 1 0) type twins arising from a-a-c+ tilt system with the presence of anti-phase domain boundaries from the displacement of A-site cations of the orthorhombic perovskite structure. {\textcopyright} 2006 Elsevier Ltd. All rights reserved.",

keywords = "Microwave dielectrics",

author = "Ravi, {G. A.} and F. Azough and R. Freer",

note = "Univ Oulu, Microwave Electroceram Grp European Ceram Soc Amer Ceram Ravi, G. A. Azough, F. Freer, R. 14 OXFORD 8-9 Sp. Iss. SI 165UP; 4th International Conference on Microwave Materials and Their Applications (MMA2006) ; Conference date: 12-06-2006 Through 15-06-2006",

year = "2007",

doi = "10.1016/j.jeurceramsoc.2006.11.010",

language = "English",

volume = "27",

pages = "2855--2859",

booktitle = "Journal of the European Ceramic Society|J. Eur. Ceram. Soc.",

publisher = "Elsevier BV",

address = "Netherlands",

}

Ravi, GA, Azough, F & Freer, R 2007, Effect of Al2O3 on the structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3. in Journal of the European Ceramic Society|J. Eur. Ceram. Soc.. vol. 27, Elsevier BV, pp. 2855-2859, 4th International Conference on Microwave Materials and Their Applications (MMA2006), Oulu, FINLAND, 12/06/06. https://doi.org/10.1016/j.jeurceramsoc.2006.11.010

TY - GEN

T1 - Effect of Al2O3 on the structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3

AU - Ravi, G. A.

AU - Azough, F.

AU - Freer, R.

N1 - Univ Oulu, Microwave Electroceram Grp European Ceram Soc Amer Ceram Ravi, G. A. Azough, F. Freer, R. 14 OXFORD 8-9 Sp. Iss. SI 165UP

PY - 2007

Y1 - 2007

N2 - The effect of excess Al2O3 on the densification, structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3 (CTLA) was investigated. CTLA ceramics were prepared using the conventional mixed oxide route. Excess Al2O3 in the range of 0.1-0.5 wt% was added. It was found that Al2O3 improved the densification. A phase rich in Ca and Al was found in the microstructure of Al2O3 doped samples. Additions of Al2O3 coupled with the slow cooling after sintering improved the microwave dielectric properties. CTLA ceramics with 0.25 wt% Al2O3 cooled at 5 °C/h showed high density and a uniform grain structure with εr = 46, Q × f = 38,289 and τf = +12 ppm/°C at 4 GHz. XRD and TEM examinations showed the presence of (1 1 2) and (1 1 0) type twins arising from a-a-c+ tilt system with the presence of anti-phase domain boundaries from the displacement of A-site cations of the orthorhombic perovskite structure. © 2006 Elsevier Ltd. All rights reserved.

AB - The effect of excess Al2O3 on the densification, structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3 (CTLA) was investigated. CTLA ceramics were prepared using the conventional mixed oxide route. Excess Al2O3 in the range of 0.1-0.5 wt% was added. It was found that Al2O3 improved the densification. A phase rich in Ca and Al was found in the microstructure of Al2O3 doped samples. Additions of Al2O3 coupled with the slow cooling after sintering improved the microwave dielectric properties. CTLA ceramics with 0.25 wt% Al2O3 cooled at 5 °C/h showed high density and a uniform grain structure with εr = 46, Q × f = 38,289 and τf = +12 ppm/°C at 4 GHz. XRD and TEM examinations showed the presence of (1 1 2) and (1 1 0) type twins arising from a-a-c+ tilt system with the presence of anti-phase domain boundaries from the displacement of A-site cations of the orthorhombic perovskite structure. © 2006 Elsevier Ltd. All rights reserved.

KW - Microwave dielectrics

U2 - 10.1016/j.jeurceramsoc.2006.11.010

DO - 10.1016/j.jeurceramsoc.2006.11.010

M3 - Conference contribution

VL - 27

SP - 2855

EP - 2859

BT - Journal of the European Ceramic Society|J. Eur. Ceram. Soc.

PB - Elsevier BV

T2 - 4th International Conference on Microwave Materials and Their Applications (MMA2006)

Y2 - 12 June 2006 through 15 June 2006

ER -

Effect of Al2O3 on the structure and microwave dielectric properties of Ca0.7Ti0.7La0.3Al0.3O3

Abstract

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