Browse > Article
http://dx.doi.org/10.6111/JKCGCT.2020.30.3.103

Microstructure and dielectric properties in the La2O3-doped BaTiO3 system  

Choi, Woo-Jin (School of Materials Science & Engineering, Department of Materials Engineering and Convergence Technology, Gyeongsang National University)
Moon, Kyoung-Seok (School of Materials Science & Engineering, Department of Materials Engineering and Convergence Technology, Gyeongsang National University)
Publication Information
Journal of the Korean Crystal Growth and Crystal Technology / v.30, no.3, 2020 , pp. 103-109 More about this Journal
Abstract
The effect of La2O3 addition on the crystalline phase, microstructure, and dielectric properties of BaTiO3 has been studied as a function of the amounts of La2O3. 0.3 mol% TiO2-excess BaTiO3 powder was synthesized by solid-state reaction, and then the powder compacts with various amounts of La2O3 were sintered at 1250℃ for 2 hours. Room temperature XRD showed changes in the lattice parameters and a decrease of tetragonality (c/a) as the amounts of La2O3 increased. It can be explained that the phase transition from tetragonal to cubic phase occurred because La3+ replaced Ba2+ site, which increased the instability of the tetragonal phase. As La2O3 was added over 0.1 mol%, the critical driving force for growth (Δgc) increased over maximum driving force (Δgmax). As the result, the grain size decreased with La2O3 addition. Dielectric constant decreased as the amounts of La2O3 increased, which was analyzed with crystal structure and microstructure.
Keywords
$BaTiO_3$; Dielectric; Microstructure; Crystal structure; Grain growth;
Citations & Related Records
연도 인용수 순위
  • Reference
1 F.D. Morrison, A.M. Coats, D.C. Sinclair and A.R. West, "Charge compensation mechanisms in La-doped $BaTiO_3$", J. Electroceram. 6 (2001) 219.   DOI
2 F.D. Morrison, D.C. Sinclair and A.R. West, "An alternative explanation for the origin of the resistivity anomaly in La-doped $BaTiO_3$", J. Am. Ceram. Soc. 84 (2001) 474.   DOI
3 J.-I. Itoh, D.-C. Park, N. Ohashi, I. Sakaguchi, I. Yashima, H. Haneda and J. Tanaka, "Oxygen defects related to electrical properties of La-doped $BaTiO_3$", Jpn. J. Appl. Phys. 41 (2002) 3798.   DOI
4 V. Paunovic, L. Zivkovic and V. Mitic, "Influence of rare-earth additives (La, Sm and Dy) on the microstructure and dielectric properties of doped $BaTiO_3$ ceramics", Sci. Sintering 42 (2010) 69.   DOI
5 C. Randall, R. Newnham and L. Cross, "History of the first ferroelectric oxide, $BaTiO_3$", Materials Research Institute, The Pennsylvania State University, University Park, Pa, USA (2004) 1.
6 Y. Sakabe, Y. Hamaji, H. Sano and N. Wada, "Effects of rare-earth oxides on the reliability of X7R dielectrics", Japanese J. Appl. Phys. 41 (2002) 5668.   DOI
7 O. Saburi, "Semiconducting bodies in the family of barium titanates", J. Am. Ceram. Soc. 44 (1961) 54.   DOI
8 J. Daniels, K. Hardtl and R. Wernicke, "The PTC effect of barium titanate", Philps Technical Review 38 (1978) 73.
9 Y. Chen and S. Yang, "PTCR effect in donor doped barium titanate: review of compositions, microstructures, processing and properties", Adv. Appl. Ceram. 110 (2011) 257.   DOI
10 Y.M. Chiang and T. Takagi, "Grain-boundary chemistry of barium titanate and strontium titanate: II, origin of electrical barriers in positive-temperature-coefficient thermistors", J. Am. Ceram. Soc. 73 (1990) 3286.   DOI
11 D.C. Sinclair and J.P. Attfield, "The influence of A-cation disorder on the Curie temperature of ferroelectric $ATiO_3$ perovskites", Chem. Commun. 16 (1999) 1497.
12 F.D. Morrison, D.C. Sinclair and A.R. West, "Doping mechanisms and electrical properties of La-doped $BaTiO_3$ ceramics", Int. J. Inorg. Mater. 3 (2001) 1205.   DOI
13 M. Vijatovic, B. Stojanovic, J. Bobic, T. Ramoska and P. Bowen, "Properties of lanthanum doped $BaTiO_3$ produced from nanopowders", Ceram. Int. 36 (2010) 1817.   DOI
14 G. Arlt, D. Hennings and G. De With, "Dielectric properties of fine-grained barium titanate ceramics", J. Appl. Phys. 58 (1985) 1619.   DOI
15 N. Wada, H. Tanaka, Y. Hamaji and Y. Sakabe, "Microstructures and dielectric properties of fine-grained $BaTiO_3$ ceramics", Jpn. J. Appl. Phys. 35 (1996) 5141.   DOI
16 T. Hoshina, K. Takizawa, J. Li, T. Kasama, H. Kakemoto and T. Tsurumi, "Domain size effect on dielectric properties of barium titanate ceramics", Jpn. J. Appl. Phys. 47 (2008) 7607.   DOI
17 T. Hoshina, "Size effect of barium titanate: fine particles and ceramics", J. Ceram. Soc. Japan, 121 (1410) (2013) 156.   DOI
18 D. Ghosh, A. Sakata, J. Carter, P.A. Thomas, H. Han, J.C. Nino and J.L. Jones, "Domain wall displacement is the origin of superior permittivity and piezoelectricity in $BaTiO_3$ at intermediate grain sizes", Adv. Funct. Mater. 24 (2014) 885.   DOI
19 T. Hoshina, S. Hatta, H. Takeda and T. Tsurumi, "Grain size effect on piezoelectric properties of $BaTiO_3$ ceramics", Jpn. J. Appl. Phys. 57 (2018) 0902BB.   DOI
20 S.-M. An and S.-J.L. Kang, "Boundary structural transition and grain growth behavior in $BaTiO_3$ with $Nd_2O_3$ doping and oxygen partial pressure change", Acta Materialia 59 (2011) 1964.   DOI
21 S.-J.L. Kang, "Sintering: densification, grain growth and microstructure", Elsevier (2004).
22 Y.-I. Jung, S.-J.L. Kang and D.Y. Yoon, "Coarsening of polyhedral grains in a liquid matrix", J. Mater. Res. 24 (2009) 2949.   DOI
23 L.L. Hench and J.K. West, "Principles of electronic ceramics", Wiley (1989).
24 Y.K. Cho, D.Y. Yoon and B.K. Kim, "Surface roughening transition and coarsening of NbC grains in liquid cobalt-rich matrix", J. Am. Ceram. Soc. 87 (2004) 443.   DOI
25 J.N. Wilson, J.M. Frost, S.K. Wallace and A. Walsh, "Dielectric and ferroic properties of metal halide perovskites", APL Mater. 7 (2019) 010901.   DOI
26 S.Y. Chung, S.J.L. Kang and V.P. Dravid, "Effect of sintering atmosphere on grain boundary segregation and grain growth in niobium-doped $SrTiO_3$", J. Am. Ceram. Soc. 85 (2002) 2805.   DOI
27 K.-S. Moon, D. Rout, H.-Y. Lee and S.-J.L. Kang, "Effect of $TiO_2$ addition on grain shape and grain coarsening behavior in $95Na_{1/2}Bi_{1/2}TiO_3-5BaTiO_3$", J. Eur. Ceram. Soc. 31 (2011) 1915.   DOI
28 A. Ianculescu, Z. Mocanu, L. Curecheriu, L. Mitoseriu, L. Padurariu and R. Trusca, "Dielectric and tunability properties of La-doped $BaTiO_3$ ceramics", J. Alloys Compd. 509 (2011) 10040.   DOI
29 H.-I. Hsiang, F.-S. Yen and C.-Y. Huang, "Effects of porosity on dielectric properties of $BaTiO_3$ ceramics", Jpn. J. Appl. Phys. 34 (1995) 1922.   DOI