Colossal Permittivity and Dielectric Relaxations of (Nb, Al)Co-doped BaTiO3 Ceramics

doi:10.15541/jim20160280

Abstract

Abstract:

Nb and Al co-doped BaTiO₃ ceramics, BaTi_0.98(Nb_0.5Al_0.5)_0.02O₃, have a colossal permittivity (ε_r≈3×10⁵, tanδ≈0.2) at room-temperature. Three distinct relaxation processes are observed in the frequency range from 10^-1 to 10⁷ Hz. The low-frequency relaxation between 10^-1 and 10 Hz and the intermediate-frequency relaxation between 10³ and 10⁵ Hz are non-Debye relaxations, which are attributed to Maxwell-Wagner interfacial polarization, electrode interfacial polarization, and barrier layer capacitor. While the high-frequency process between 10⁵ and 10⁷ Hz is a typical Debye-type relaxation with an activation energy of E≈15 meV and a frequency factor of f₀≈7×10⁶ Hz. The small activation energy and relatively small frequency factor in the BaTi_0.98(Nb_0.5Al_0.5)_0.02O₃ ceramics indicate that this relaxation process may derive from local motion of electrons in the complex defect clusters, which results from co-doping and can be named as electron-pinned defect-dipoles. This study suggests that the electron-pinned defect-dipoles mechanism can be used to design colossal permittivity in perovskites, like BaTiO₃.

Key words: (Nb, Al) co-doped, perovskites, colossal permittivity, electron-pinned defect-dipoles

CLC Number:

TQ174

HUANG Dong, WU Ying, MIAO Ji-Yuan, LIU Zhi-Fu, LI Yong-Xiang. Colossal Permittivity and Dielectric Relaxations of (Nb, Al)Co-doped BaTiO₃ Ceramics[J]. Journal of Inorganic Materials, 2017, 32(2): 219-224.

Figures/Tables 6

Fig. 1 shows the temperature dependence of dielectric spectra of BTNA and pure BaTiO3 ceramics. Comparing to BaTiO3, the permittivity of BTNA is significantly improved. Colossal permittivity, εr >105, is observed for BTNA ceramic sample between 150 K and 450 K. Meanwhile, the temperature stability of BTNA is also enhanced. There is no permittivity peak related to the phase transition which is observed in the BaTiO3 sample. The permittivity shows a relatively flat platform at the temperature range from 280 K to 370 K. The considerable improvement of permittivity and its temperature stability in BTNA demonstrates that its CP doesn’t originate from ferroelectricity. No impurity phase is found in XRD pattern and the shift of the diffraction peaks implies that Nb and Al have been introduced into the lattice of the BaTiO3 crystal grains. The microstructural and elemental investigation also show the uniform distribution of dopants. And the BTNA ceramic is single tetragonal phase, the same as BaTiO3[11]. Hence, the CP should not be from other phases.

Fig. 1 Temperature dependence of permittivity and dielectric loss for BaTiO3 ceramic sintered at 1623 K/6 h and BTNA ceramic sintered at 1593 K/6 h in temperature range from 123 K to 459 K

Fig. 2 Comparison of the dependent permittivity and dielectric loss of BTNA, CaCu3Ti4O12[12], (Li, Ti) co-doped NiO[14], (Nb, In) co-doped TiO2[8] and spark plasma sintered BaTiO3[13] in the frequency range from 10 Hz to 107 Hz

Fig. 3 Frequency dependence of the dielectric loss of BTNA ceramic in the frequency range from 10 Hz to 107 Hz measured from 143 K to 383 K. The inset shows the M’’ spectroscopic plots for the BTNA at low frequency range (0.04 Hz to 10 Hz)

Fig. 4 The dependence of dielectric loss peak frequency on testing temperature from 143 K to 383 K

Fig. 5 Core level XPS (open circles) and corresponding fitting results (solids lines) of BTNA sample

References 34

[1]	LUNKENHEIMER P, KROHNS S, RIEGG S,et al. Colossal dielectric constants in transition-metal oxides.The European Physical Journal Special Topics, 2010, 180(1): 61-89.
[2]	KROHNS S, LUNKENHEIMER P, MEISSNER S,et al. The route to resource-efficient novel materials.Nature Materials, 2011, 10(12): 899-901.
[3]	HOMES C C, VOGT T, SHAPIRO S M,et al. Optical response of high-dielectric-constant perovskite-related oxide.Science, 2001, 293(5530): 673-676.
[4]	LI Y X.Some hot topics in electroceramics research.Journal of Inorganic Materials, 2014, 29(1): 1-5.
[5]	SARKAR S, JANA P K, CHAUDHURI B. Colossal internal barrier layer capacitance effect in polycrystalline copper(II)oxide. Applied Physics Letters, 2008, 92(2): 022905-1-3.
[6]	CAVA R J, FLEMING R M, LITTLEWOOD P,et al. Dielectric response of the charge-density wave in K0.3MoO3.Physical Review B, 1984, 30(6): 3228-3239.
[7]	IKEDA N, OHSUMI H, OHWADA K,et al. Ferroelectricity from iron valence ordering in the charge-frustrated system LuFe2O4.Nature, 2005, 436(7054): 1136-1138.
[8]	HU W B, LIU Y, WITHERS R L,et al. Electron-pinned defect-dipoles for high-performance colossal permittivity materials.Nature Materials, 2013, 12(9): 821-826.
[9]	MAGLIONE M, BELKAOUMI M.Electron relaxation-mode interaction in BaTiO3-Nb. Physical Review B, 1992, 45(5): 2029-2034.
[10]	JANOTTI A, VARLEY J B, CHOI M, et al. Vacancies. Vacancies and small polarons in SrTiO3.Physical Review B, 2014, 90(8): 085202-1-3.
[11]	BEN L B, SINCLAIR D C. Anomalous curie temperature behavior of A-site Gd-doped BaTiO3 ceramics: the influence of strain.Applied Physics Letters, 2011,98(9): 092207-1-3.
[12]	PATTERSON E A, KWON S, HUANG C C, et al. Effects of ZrO2 additions on the dielectric properties of CaCu3Ti4O12.Applied Physics Letters, 2005,87(18): 182911-1-3.
[13]	HAN H, VOISIN C, GUILLEMET-FRITSCH S, et al. Origin of colossal permittivity in BaTiO3 via broadband dielectric spectroscopy.Journal of Applied Physics.2013, 113(2): 024102-1-3.
[14]	WU J, NAN C W, LIN Y, et al. Giant dielectric permittivity observed in Li.Giant dielectric permittivity observed in Li and Ti doped NiO.Physical Review Letters, 2002,89(21): 217601-1-3.
[15]	JONSCHER A K. Dielectric relaxation in solids.Journal of Physics D: Applied Physics, 1999,32(14): R57-1-3.
[16]	KROHNS S, LUNKENHEIMER P, KANT C, et al. Colossal dielectric constant up to gigahertz at room temperature.Applied Physics Letters, 2009,94(12): 122903-1-3.
[17]	WANG H, LI G, ZHAO M, et al. Spin state transition and giant dielectric constant in Pr0.987Na0.013CoO3.Applied Physics Letters.2012,100(15): 152109-1-3.
[18]	LI X, XU L, LIU L,et al. High pressure treated ZnO ceramics towards giant dielectric constants.Journal of Materials Chemistry A, 2014, 2(39): 16740-16745.
[19]	WAGNER K W.The theory of incomplete dielectricity.Annalen Der Physik, 1913, 40(5): 817-855.
[20]	KOLODIAZHNYI T, TACHIBANA M, KAWAJI H, et al. Persistence of ferroelectricity in BaTiO3 through the insulator-metal transition.Physical Review Letters,2010,104(14): 147602- 1-3.
[21]	KATAOKA N, HAYASHI K, YAMAMOTO T,et al. Direct observation of the double Schottky barrier in niobium-doped barium titanate by the charge-collection current method.Journal of American Ceramics Society, 1998, 81(7): 1961-1963.
[22]	BIDAULT O, GOUX P, KCHIKECH M,et al. Space-charge relaxation in perovskites.Physical Review B, 1994, 49(12): 7868-7873.
[23]	BIDAULT O, MAGLIONE M, ACTIS M,et al. Polaronic relaxation in perovskites.. Physical Review B, 1995, 52(6): 4191-4197.
[24]	ANDERSON P W.Absence of diffusion in certain random lattices.Physical Review, 1958, 109(5): 1492-1505.
[25]	LEMANOV V V, SOTNIKOV A V, SMIRNOVA E P,et al. Giant dielectric relaxation in SrTiO3-SrMg1/3Nb2/3O3 and SrTiO3-SrSc1/2 Ta1/2O3 solid solutions. Physics of the Solid State, 2002, 44(11): 2039-2049.
[26]	DOMINIK L A K, MACCRONE R K. Dielectric relaxations in reduced rutile TiO2-x at low temperatures.Physical Review, 1967, 163(3): 756.
[27]	RAMOS-MOORE E, FERRARI P, DIAZ-DROGUETT D E, et al.Raman and X-ray photoelectron spectroscopy study of ferroelectric switching in Pb(Nb,Zr,Ti)O3 thin films.Journal of Applied Physics, 2012,111(1): 014108-1-3.
[28]	SHUAI Y, ZHOU S, BUERGER D, et al. Decisive role of oxygen vacancy in ferroelectric versus ferromagnetic Mn-doped BaTiO3 thin films.Journal of Applied Physics, 2011,109(8): 084105-1-3.
[29]	NASSER S A.X-ray photoelectron spectroscopy study on the composition and structure of BaTiO3 thin films deposited on silicon.Applied Surface Science, 2000, 157(1/2): 14-22.
[30]	CHAN N H, SHARMA R, SMYTH D M.Nonstoichiometry in acceptor‐doped BaTiO3.Journal of American Ceramics Society, 1982, 65(3): 167-170.
[31]	YANG N H, TSENG C C, WU J L,et al. One-step molten-salt synthesis of BaTi4O9 nanowires with oxygen deficiency-enhanced dielectric performance.RSC Advances, 2013, 3(19): 7093-7099.
[32]	LI W, ZHAO R, WANG L,et al. Oxygen-vacancy- induced antiferromagnetism to ferromagnetism transformation in Eu0.5Ba0.5TiO3-δ multiferroic thin films.Scientific Reports, 2013, 3: 2618.
[33]	CHAN N H, SMYTH D M.Defect chemistry of donor‐doped BaTiO3.Journal of American Ceramics Society, 1984, 67(4): 285-288.
[34]	GAI Z, CHENG Z, WANG X,et al. A colossal dielectric constant of an amorphous TiO2:(Nb, In) film with low loss fabrication at room temperature.Journal of Materials Chemistry C, 2014, 2(33): 6790-6795.

Colossal Permittivity and Dielectric Relaxations of (Nb, Al)Co-doped BaTiO₃ Ceramics

RichHTML

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 6

References 34

Related Articles 3

Recommended Articles

Metrics

Comments

[1]	XU Tingting, LI Yunyun, WANG Qian, WANG Jingkang, REN Guohao, SUN Dazhi, WU Yuntao. Centimeter-sized Cs₃Cu₂I₅ Single Crystal: Synthesized by Low-cost Solution Method and Optical and Scintillation Properties [J]. Journal of Inorganic Materials, 2022, 37(10): 1129-1134.
[2]	LIU Tao. Preparation and Characterization of Sr_1-_xTb_xCoO_3-_δ (x≤0.3) Cathode Materials for Intermediate-temperature Solid Oxide Fuel Cell [J]. Journal of Inorganic Materials, 2013, 28(2): 212-216.
[3]	ZHAO Chang-Lei,FENG Chu-De. Fabrication and Ordering Behavior of Lead Magnesium Niobate Ceramics Doped with Bismuth Cations [J]. Journal of Inorganic Materials, 2000, 15(1): 103-108.