Tantalum Vacancy Effects on Electrical Conductivity of La3Ta0.5Ga5.5O14 and Ba-Based P321 Crystals

Article Preview

Abstract:

Single Crystalline Langatate (La3Ta0.5Ga5.5O14, 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.

You might also be interested in these eBooks

Info:

Periodical:

Pages:

325-330

Citation:

Online since:

March 2012

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2012 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] H. Fritze, High-temperature piezoelectric crystals and devices, J. Electroceram. 26 (2011) 122-161.

DOI: 10.1007/s10832-011-9639-6

Google Scholar

[2] R. Yaokawa, S. Uda, H. Kimura, K. Aota, Electrical conduction mechanism in nonstoichiometric La3Ta0. 5Ga5. 5O14, J. Appl. Phys. 108 (2010) 064112.

DOI: 10.1063/1.3478772

Google Scholar

[3] C. -Y. Chung, R. Yaokawa, H. Mizuseki, S. Uda, Y. Kawazoe, First principles calculation of La3Ta0. 5Ga5. 5O14 crystal with acceptor-like intrinsic point defects, J. Appl. Phys. 108 (2010) 113505.

DOI: 10.1063/1.3514008

Google Scholar

[4] H. Takeda, H. Nakao, S. Izukawa, H. Shimizu, T. Nishida, S. Okamura, T. Shiosaki, Growth and piezoelectric porperties of R3Ga5SiO14 and RCa4O(BO3)3 (R: rare-earth elements) single crystals, J. Alloy. Compd. 408-412 (2006) 474-479.

DOI: 10.1016/j.jallcom.2004.12.108

Google Scholar

[5] C. -Y. Chung, R. Yaokawa, H. Mizuseki, Y. Kawazoe, Atomistic configuration effects on piezoelectric properties of La3Ta0. 5Ga5. 5O14 and a new piezoelectric crystal design, Acta Mater. 59 (2011) 6473-6479.

DOI: 10.1016/j.actamat.2011.07.011

Google Scholar

[6] P. B. Allen, Boltzmann theory and resistivity of metals, in: J. Chelikowsky, S. Louie (Eds. ), Quantum Theory of Real Materials, Kluwer, Boston, 1996, pp.219-250.

DOI: 10.1007/978-1-4613-0461-6_17

Google Scholar

[7] M. J. Gillan, Calculation of the vacancy formation energy in aluminum, J. Phys.: Condens. Matter. 1 (1989) 689-711.

Google Scholar

[8] M. Shiskin, G. Kresse, Implementation and performance of the frequency-dependent GW method within the PAW framework, Phys. Rev. B 74 (2006) 035101.

Google Scholar

[9] J. P. Perdew, K. Burke, M. Ernzerhof, Generalized gradient approximation made simple, Phys. Rev. Lett. 77 (1996) 3865-3868.

DOI: 10.1103/physrevlett.77.3865

Google Scholar

[10] G. Kresse, J. Furthmuller, Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set, Comput. Mater. Sci. 6 (1996) 15-50.

DOI: 10.1016/0927-0256(96)00008-0

Google Scholar

[11] G. K.H. Madsen, D. J. Singh, BoltzTraP. A code for calculating band-structure dependent quantities, Comput. Phys. Commun. 175 (2006) 67-71.

DOI: 10.1016/j.cpc.2006.03.007

Google Scholar

[12] A. P. Dudka, B. V. Mill, Yu. V. Pisarevsky, Refinement of the crystal structures of the La3Ta0. 5Ga5. 5O14 and La3Nb0. 5Ga5. 5O14 compounds, Crystallogr. Rep. 54 (2009) 558-567.

DOI: 10.1134/s106377450904004x

Google Scholar

[13] F.A. Kröger, H. J. Vink, in: F. Seitz, D. Turnbull, Solid State Physics vol. 3, Academic Press, New York, 1956, pp.273-301.

Google Scholar