Tantalum vacancy effects on electrical conductivity of La 3Ta0.5Ga5.5O14 and Ba-based P321 crystals

Chan Yeup Chung, Ritsuko Yaokawa, Hiroshi Mizuseki, Yoshiyuki Kawazoe

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Single crystalline langatate (La3Ta0.5Ga 5.5O14, LTG) has been widely used in piezoelectric sensors for high temperature applications because of its structural stability at high temperature. However, in the recent experiment, an increase of electrical conductivity has been also observed at the intermediate temperature region ranges from 300 to 700°C. Also, in theoretical calculations, penta-valent Ta vacancy can be easily generated and influence resistivity degradation of the crystal. In this study, to elucidate the Ta vacancy effects on electrical conductivity of LTG and recently proposed Ba-based P321 crystal such as BTGS and BTAS, electrical conductivity of those materials were calculated and compared by utilizing Boltzmann transport theory. The calculated GW band gaps of perfect BTGS and BTAS (5.94 eV and 6.69 eV, respectivily) were much larger than that of LTG (5.36 eV). Also, at intermediate temperature (1000K), the calculated electrical conductivity of LTG with V‴ Ta (in Kröger-Vink notation [13]) was around twelve times higher than the conductivity of BTGS and BTAS with Ta vacancy.

Original languageEnglish
Title of host publicationMaterials Integration
PublisherTrans Tech Publications Ltd
Pages325-330
Number of pages6
ISBN (Print)9783037853764
DOIs
Publication statusPublished - 2012
EventInt. Symposium of GCOE: Materials Integration, in Conjunction with the 2nd Int. Symposium on Advanced Synthesis and Processing Technology for Materials, ASPT 2011 and the 8th Materials Science School for Young Scientists, KINKEN-WAKATE 2011 - Sendai, Japan
Duration: 2011 Dec 12011 Dec 2

Publication series

NameKey Engineering Materials
Volume508
ISSN (Print)1013-9826
ISSN (Electronic)1662-9795

Other

OtherInt. Symposium of GCOE: Materials Integration, in Conjunction with the 2nd Int. Symposium on Advanced Synthesis and Processing Technology for Materials, ASPT 2011 and the 8th Materials Science School for Young Scientists, KINKEN-WAKATE 2011
CountryJapan
CitySendai
Period11/12/111/12/2

Keywords

  • Boltzmann transport calculation
  • Density functional theory
  • First principles calculation
  • GW calculation
  • Langatate
  • Ta vacancy

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Tantalum vacancy effects on electrical conductivity of La <sub>3</sub>Ta<sub>0.5</sub>Ga<sub>5.5</sub>O<sub>14</sub> and Ba-based P321 crystals'. Together they form a unique fingerprint.

Cite this