Volume 94, Issue 3 p. 736-741

Dielectric and Ferroelectric Characterization of Ba0.95Tm0.05TiO3 Ceramics Derived from Sol to Gel

Marin Cernea

Corresponding Author

Marin Cernea

National Institute of Materials Physics, Bucharest RO-77125, Romania

Author to whom correspondence should be addressed. e-mail: [email protected]Search for more papers by this author
Bogdan S. Vasile

Bogdan S. Vasile

Department of Science and Engineering of Oxide Materials and Nanomaterials, University Polithnica of Bucharest, 011061 Bucharest, Romania

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Paul Ganea

Paul Ganea

National Institute of Materials Physics, Bucharest RO-77125, Romania

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Roxana Radu

Roxana Radu

National Institute of Materials Physics, Bucharest RO-77125, Romania

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Valentina Mihalache

Valentina Mihalache

National Institute of Materials Physics, Bucharest RO-77125, Romania

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Adrian Husanu

Adrian Husanu

National Institute of Materials Physics, Bucharest RO-77125, Romania

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First published: 04 November 2010
Citations: 4

M. P. Paranthaman—contributing editor

This work was supported by the “Nucleu”-project, PN09-450102, from the National plan for RDI, funded by the Romanian Ministry of Education and Research, and the National Authority for Scientific Research.

Abstract

Barium titanate (BaTiO3) has been doped in situ with 5 mol% thulium by a sol–gel method. The as-prepared gel powder consists of nanosized grains (20–30 nm) and crystallizes on the cubic BaTiO3 lattice, at 700°C. Ba0.95Tm0.05TiO3 ceramics derived from this powder have tetragonal perovskite structure and contain a small amount of Tm2Ti2O7 pyrochlore phase. These ceramics exhibit dielectric constants of 4282–3240 and dielectric loss (tan δ) of 0.1077–0.0161 at Curie temperature Tc=132°C and at 10 Hz–100 kHz, respectively. For a drive voltage of 400 V, the hysteresis loop recorded at the frequency of 100 Hz shows a remnant polarization (Pr) value of 76 μC/cm2 and a coercive field (Ec) of 124 V and for 1 kHz a remnant polarization (Pr) value of 58 μC/cm2 and a coercive field (Ec) of 116 V.