JZUS - Journal of Zhejiang University SCIENCE

Journal of Zhejiang University SCIENCE A 2008 Vol.9 No.3 P.429-434

Study of the behaviour of the dielectric constant in Cu,Fe:BaTiO₃

Author(s): Alioune OUEDRAOGO, Kalifa PALM, Issaka OUEDRAOGO, Guy CHANUSSOT
Affiliation(s): Laboratory of Applied Organic Chemistry and Physics, UFR/SEA, University of Ouagadougou, BP 7021 Ouagadougou, Burkina Faso; more
Corresponding email(s): alioue@univ-ouaga.bf
Key Words: No Keyword

Share this article to： More <<< Previous Article \|

Abstract: In this work we study the behaviour of the dielectric constant of BaTiO₃ single crystals doped with Cu and Fe for different ion percentages, particularly, the influence of these heterovalent substitutions on the ferroelectric-paraelectric phase transition whose temperature is found at T_c=120 °C for pure samples. The dielectric constant ε in terms of temperature shows that the Curie temperature decreases when the quantity of impurities increases and presents a broadening and flattering of the maximum of ε(T) within higher values, with the transition becoming more and more diffuse. It is interesting to have a material with very high permittivity (high-k) because of its capacity to store an important quantity of electric charges. The ε anisotropy and the Curie-Weiss law are also verified with a good ratio between the slopes of ε⁻¹(T) from both sides of the transition, leading to a Curie constant: C=13×10⁴ K for BaTiO₃:1.6%Fe in the polar phase. BaTiO₃ is a displacive ferroelectric going through a first-order phase transition. The substitutions have an effect on the dynamics of the perovskite lattice. They induce charges transfer to Ti and a diminution of elastic forces in BaTiO₃. Then we discuss the fact that the maximum of permittivity does not depend on the phase transition but on the nature of the material.

Reference

[1] Abdulraheem, Y.M., Gentile, A.L., Stafsudd, O.M., 2006. The effects of iron as a dopant on the dielectric properties of ferroelectric potassium tantalite niobate. Journal of Applied Physics, 100(10):104111-104118.

[2] Akira, I., Michiaki, I., Matsuda, I., Hirimoto, U., Tunetaro, S., 1991. Effect of iron-group-ion doping on the properties of BaTiO₃ ceramics. Japanese Journal of Applied Physics, 30(9A):2388-2390.

[3] Bernaben, N., 1996. Fine Grained Ceramics of Barium Titanate: Relationship between the Dielectric Behaviour and the Microstruture. Ph.D Thesis, University of Dijon. Travaux Universitaires: 96 Dijo.

[4] Bidault, O., Maglione, M., Actis, M., Kchikech, M., Salce, B., 1995. Polaronic relaxation in perovskites. Physical Review B, 52(6):4191-4197.

[5] Boccara, N., 1981. Symmetries and Broken Symmetries in Condensed Matter in Physics. DSET, Paris.

[6] Chanussot, G., Ouedraogo, A., 1981. Random electronic effects in ferroelectric lattices: an example. Ferroelectrics, 31:160-172.

[7] Chen, A., Zhi, J., Zhi, Y., 1999. Variable-range-hopping conduction and metal-insulator transition in Cu-doped BaTiO₃. Journal of Physics Condensed Matter, 11(48):9703-9708.

[8] Choi, J., Dowben, P.A., Borca, C.N., Adenwalla, S., Bune, A.V., Ducharme, S., Fridkin, V.M., Palto, S.P., Petukhova, N., 1999. Evidence of dynamic Jann-Teller distortions in two-dimensional crystalline molecular films. Physical Review B, 59(3):1819-1824.

[9] CIRIMAT, 2005. Activities Report OVM. University of Paul Sabatier. Toulouse.

[10] Devonshire, A.F., 1949. Theory of barium titanate. Philosophical Magazine, 40:1040-1065.

[11] Guillan, J., 2005. Study of Metallic Oxides Thin Layers Capacitors with very High Permittivity: BaTiO₃, SrTiO₃ and BaTiO₃/SrTiO₃ Deposited by Ions Beam Sputtering. Ph.D Thesis, Joseph Fourier University of Grenoble.

[12] Kchikech, M., Maglione, E., M., 1993. Influence of Heterovalent Substitutions on the Lattice Dynamics and the Conduction in Perovskites: Applications to BaTiO₃:La and BaTiO₃:Cu. Ph.D Thesis, University of Dijon. Travaux Universitaires: 93 Dijo: 9033 Dijon.

[13] Khalal, A., Kathib, D., Jannot, B., 1999a. Theoretical study of lattice dynamics in the tetragonal phase of BaTiO₃. Annales de Chimie Science des Matériaux, 24(7):471-490.

[14] Khalal, A., Kathib, D., Jannot, B., 1999b. Elastic and piezoelectric properties of BaTiO₃ at room temperature. Physica B: Condensed Matter, 271(1-4):343-347.

[15] Knauer, U., 1979. Distribution of the iron dopant in barium titanate ceramic determined by the scanning transmission electron microscope. Physica Status Solidi (a), 53(1):207-210.

[16] Mathey, P., Jullien, P., Lompre, P., Rytz, D., 1998. Photorefractive detection of antiparallel ferroelectric domains in BaTiO₃ and BaTiO₃:Cu crystals. Applied Physics A: Materials Science & Processing, 66(5):511-514.

[17] Matthias, B.T., von Hippel, A., 1948. Domain structure and dielectric response of barium titanate single crystals. Physical Review, 73(11):1378-1384.

[18] Merz, W.J., 1949. The electrical and optical behaviour of BaTiO₃ single domain crystals. Physical Review, 76(8):1221-1225.

[19] Merz, W.J., 1951. The dielectric properties of BaTiO₃ at room temperatures. Physical Review, 81(6):1064-1065.

[20] Ouedraogo, A., 2002. Study of Phase Transitions in Pure and Doped BaTiO₃ and Structural Instabilities in Sn₂P₂Se₆. Ph.D Thesis, University of Ouagadougou.

[21] Ouedraogo, A., 2003. Deformations and vibrations of the octahedral TiO₆: application to BaTiO₃. Journal de la Société Ouest Africaine de Chimie, 015:115-126.

[22] Ouedraogo, A., Chanussot, G., 1998. Intrinsic photoconductivity in pulsed regime in BaTiO₃ pulled crystals. Annales de l’Université de Ouagadougou B, VI:259-269.

[23] Ouedraogo, A., Chanussot, G., Berger, H., 1978. Determination of the phase transitions of BaTiO₃ type crystals by using the theory of symmetry breaking. Solid State Communications, 27(2):159-161.

[24] Papon, P., Leblond, L., Meiger, P.H., 1999. Physique des Transitions de Phases. Dunod, Paris.

[25] Remeika, J.P., 1954. A method for growing barium titanate single crystals. Journal of the American Chemistry Society, 76(3):940-941.

[26] Tsygankov, V.N., Safonov, V.V., 2002. Doping effects on the properties of BaTiO₃ based on solid solutions. Inorganic Materials, 38(4):397-399.

Open peer comments: Debate/Discuss/Question/Opinion

<1>

Similar articles

- Go to

Darkslateblue:Affiliate; Royal Blue:Author; Turquoise:Article

Reference