Microstructural and electrical characterisation of LaxBa 1-xTi1-xYxO3 (0≤ x ≤ 0.50) ceramics

A. Feteira, D. C. Sinclair, Michael T. Lanagan

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

LaxBa1-xTi1-xYxO3 (0≤x≤0.5) powders were synthesised in air at 1400°C by the conventional solid state method. According to the X-ray results, the tetragonal distortion in undoped (x=0) BaTiO3 (space group P4mm) decreases with x and samples with x ≥0.05 show cubic symmetry (space group Pm3 m). For x≥0.05, the lattice parameter increases linearly with x, until orthorhombic LaYO3 appears as a secondary phase for x>0.45. Dielectric properties of dense (>95% of the theoretical X-ray density) ceramics were studied at both radio and microwave frequencies. The permittivity maximum is shifted towards lower temperatures with increasing x and a broad permittivity peak is observed for samples with 0.05<x<0.30. These samples exhibit a dielectric response typical of "relaxor"-type materials. In contrast, ceramics with x=0.40 exhibit almost temperature independent dielectric properties (τf=+12 ppm/K) and although they resonate at microwave frequencies they have low quality factors (Q.f≤ 755 at ∼5 GHz). Finally, conventional transmission electron microscopy combined with electron diffraction studies were carried out to provide a better understanding of structure-property relationships in LaxBa1-xTi 1-xYxO3 ceramics.

Original languageEnglish (US)
Pages (from-to)873-876
Number of pages4
JournalKey Engineering Materials
Volume317-318
StatePublished - Jul 24 2006

Fingerprint

Microwave frequencies
Dielectric properties
Permittivity
X rays
Electron diffraction
Powders
Lattice constants
Transmission electron microscopy
Temperature
Air

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

@article{0776ff7e4e8d4c8f81d8fe520f40950c,
title = "Microstructural and electrical characterisation of LaxBa 1-xTi1-xYxO3 (0≤ x ≤ 0.50) ceramics",
abstract = "LaxBa1-xTi1-xYxO3 (0≤x≤0.5) powders were synthesised in air at 1400°C by the conventional solid state method. According to the X-ray results, the tetragonal distortion in undoped (x=0) BaTiO3 (space group P4mm) decreases with x and samples with x ≥0.05 show cubic symmetry (space group Pm3 m). For x≥0.05, the lattice parameter increases linearly with x, until orthorhombic LaYO3 appears as a secondary phase for x>0.45. Dielectric properties of dense (>95{\%} of the theoretical X-ray density) ceramics were studied at both radio and microwave frequencies. The permittivity maximum is shifted towards lower temperatures with increasing x and a broad permittivity peak is observed for samples with 0.05f=+12 ppm/K) and although they resonate at microwave frequencies they have low quality factors (Q.f≤ 755 at ∼5 GHz). Finally, conventional transmission electron microscopy combined with electron diffraction studies were carried out to provide a better understanding of structure-property relationships in LaxBa1-xTi 1-xYxO3 ceramics.",
author = "A. Feteira and Sinclair, {D. C.} and Lanagan, {Michael T.}",
year = "2006",
month = "7",
day = "24",
language = "English (US)",
volume = "317-318",
pages = "873--876",
journal = "Key Engineering Materials",
issn = "1013-9826",
publisher = "Trans Tech Publications",

}

Microstructural and electrical characterisation of LaxBa 1-xTi1-xYxO3 (0≤ x ≤ 0.50) ceramics. / Feteira, A.; Sinclair, D. C.; Lanagan, Michael T.

In: Key Engineering Materials, Vol. 317-318, 24.07.2006, p. 873-876.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Microstructural and electrical characterisation of LaxBa 1-xTi1-xYxO3 (0≤ x ≤ 0.50) ceramics

AU - Feteira, A.

AU - Sinclair, D. C.

AU - Lanagan, Michael T.

PY - 2006/7/24

Y1 - 2006/7/24

N2 - LaxBa1-xTi1-xYxO3 (0≤x≤0.5) powders were synthesised in air at 1400°C by the conventional solid state method. According to the X-ray results, the tetragonal distortion in undoped (x=0) BaTiO3 (space group P4mm) decreases with x and samples with x ≥0.05 show cubic symmetry (space group Pm3 m). For x≥0.05, the lattice parameter increases linearly with x, until orthorhombic LaYO3 appears as a secondary phase for x>0.45. Dielectric properties of dense (>95% of the theoretical X-ray density) ceramics were studied at both radio and microwave frequencies. The permittivity maximum is shifted towards lower temperatures with increasing x and a broad permittivity peak is observed for samples with 0.05f=+12 ppm/K) and although they resonate at microwave frequencies they have low quality factors (Q.f≤ 755 at ∼5 GHz). Finally, conventional transmission electron microscopy combined with electron diffraction studies were carried out to provide a better understanding of structure-property relationships in LaxBa1-xTi 1-xYxO3 ceramics.

AB - LaxBa1-xTi1-xYxO3 (0≤x≤0.5) powders were synthesised in air at 1400°C by the conventional solid state method. According to the X-ray results, the tetragonal distortion in undoped (x=0) BaTiO3 (space group P4mm) decreases with x and samples with x ≥0.05 show cubic symmetry (space group Pm3 m). For x≥0.05, the lattice parameter increases linearly with x, until orthorhombic LaYO3 appears as a secondary phase for x>0.45. Dielectric properties of dense (>95% of the theoretical X-ray density) ceramics were studied at both radio and microwave frequencies. The permittivity maximum is shifted towards lower temperatures with increasing x and a broad permittivity peak is observed for samples with 0.05f=+12 ppm/K) and although they resonate at microwave frequencies they have low quality factors (Q.f≤ 755 at ∼5 GHz). Finally, conventional transmission electron microscopy combined with electron diffraction studies were carried out to provide a better understanding of structure-property relationships in LaxBa1-xTi 1-xYxO3 ceramics.

UR - http://www.scopus.com/inward/record.url?scp=33746101746&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33746101746&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33746101746

VL - 317-318

SP - 873

EP - 876

JO - Key Engineering Materials

JF - Key Engineering Materials

SN - 1013-9826

ER -