Flux Additions in Barium Titanate: Overview and Prospects

Prakash, Deep; Sharma, B.P.; Mohan, T.R. Rama; Gopalan, P.

doi:10.1006/jssc.2000.8895

Cited by 32 publications

(29 citation statements)

References 21 publications

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“…Lowering the sintering temperature becomes more significant to prepare high piezoelectric properties in the practical applications of BaTiO 3 ceramics. Sintering aids are mostly used to lower the sintering temperature of BaTiO 3 ceramics, among which Li + -containing additives are very effective [8][9][10]. You [8] reported that the sintering temperature of (Ba,Sr)TiO 3 was reduced from 1350°C to 900°C by adding Li 2 CO 3 .…”

Section: Introductionmentioning

confidence: 98%

Low-temperature sintering of Li2O-doped BaTiO3 lead-free piezoelectric ceramics

Zhang

Yang

2012

J Electroceram

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Low-temperature sintering of BaTiO 3 ceramics using Li 2 O as sintering aids was investigated with a special influences of Li 2 O content (0-4 mol%) and sintering temperature (1000-1100°C) on crystalline structure and electrical properties. The sinterability of BaTiO 3 ceramics significantly improved by adding Li 2 O, whose densification sintering temperature reduced from 1300°C to 1000°C. XRD pattern indicated that BaTiO 3 -xLi 2 O samples were single phase with a tetragonal symmetry as x00-0.3 mol%, while the samples became an orthorhombic symmetry as x 0 0.5-4 mol%. The densification sintering temperature in which samples showed relative density higher than 90 % decreased with increasing Li 2 O content. A maximum d 33 value (200 pC/N) was obtained for the BaTiO 3 -0.5 mol%Li 2 O sample sintered at 1050°C, which is attributed to a vicinity of the phase transition and the high density. Adding Li 2 O not only reduced the sintering temperature but also obtained the acceptable piezoelectric properties, which will make BaTiO 3 become a kind of promising and practical lead-free piezoelectric ceramics.

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Section: Introductionmentioning

confidence: 98%

Low-temperature sintering of Li2O-doped BaTiO3 lead-free piezoelectric ceramics

Zhang

Yang

2012

J Electroceram

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“…1-3 B 2 O 3 -based flux additions, as a liquid phase provider at high temperatures, have received much attention to decrease the sintering temperature of BaTiO 3 based ceramics. [4][5][6][7][8][9][10] Rhim et al found that the dielectric and ferroelectric properties of Ba 0.7 Sr 0.3 TiO 3 samples with 0.5 wt % of B 2 O 3 sintered at Ͻ1150°C were as good as those of undoped Ba 0.7 Sr 0.3 TiO 3 sintered at 1350°C. 7 Prakash et al found an addition of the ZnO-B 2 O 3 flux to BaTiO 3 lowered the sintering temperature and improved its dielectric properties.…”

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confidence: 99%

“…7 Prakash et al found an addition of the ZnO-B 2 O 3 flux to BaTiO 3 lowered the sintering temperature and improved its dielectric properties. 8 Lee et al reported that various boron source compounds, such as BaB 2 O 4 , greatly lowered the starting temperature of densification by formation of liquid phases around 900°C, lowered room temperature resistivity r and improved positive temperature coefficient resistivity (PTCR) effect of Y-doped BaTiO 3 ceramics. 9 However, B 2 O 3 has rarely caused attention as a dopant rather than flux addition.…”

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confidence: 99%

Dielectric properties of barium titanate ceramics doped by B2O3 vapor

Chen

Wang

et al. 2004

Journal of Applied Physics

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The effects of B 2 O 3 vapor doping on the dielectric properties of barium titanate ceramics were studied. After the doping, the Curie point of BaTiO 3 ceramics was increased from 128°C to 130°C and the maximum dielectric constant was considerably increased. X-ray diffraction showed that both the grain lattice parameters and the tetragonality were increased by the boron oxide vapor doping. It was proposed that boron interstitial was introduced into the grain lattice of barium titanate ceramics by B 2 O 3 vapor doping and the dielectric properties were thus obviously changed. 9 However, B 2 O 3 has rarely caused attention as a dopant rather than flux addition. Because B 2 O 3 vaporizes easily at high temperatures, it can be adopted as a vapor dopant. In donor doped BaTiO 3 ceramics, the B 2 O 3 vapor dopant can improve the PTCR effect distinctly 11,12 and decrease the sintering temperature. 13 These effects were benefited from the introduction of boron interstitial in the perovskite lattice. In this paper, we focus our attention on the dielectric properties of barium titanate ceramics doped by B 2 O 3 vapor.High purity commercial BaTiO 3 (99.99%, Advanced Nano Products Co., Ltd., Chungcheongbuk-do, Korea), and B 2 O 3 (99.99%, Beijing Chemical Plant, Beijing, China) were adopted as starting materials. The barium titanate powders were pressed into small disks 1 mm thick and 10 mm in diameter with hydrostatic pressure of 98 MPa. The disks were placed in two bottom-up alumina crucibles marked as A , B, respectively. B 2 O 3 powders of 0.25 mol % (nominally) were placed beside the samples in crucible B. The samples were sintered at 1250°C for 2 h in air, then furnace cooled to room temperature. The samples in crucibles A and B were sintered in different runs to avoid cross contamination. The microstructure of the samples was studied by scanning electron microscopy (Leica Steroscan 440). The lattice parameters were measured by an x-ray diffractometer (Philips PW 3719) with Cu K a radiation. The ceramic samples were polished and silver paste electrodes were fired on both surfaces. The dielectric constant and the dielectric loss of the samples were measured through an impedance analyzer (Model HP 4192A LF, Hewlett-Packard Co., U.S.A.) from room temperature to 200°C.As temperature decreases, barium titanate undergoes three successive phase transitions: From paraelectric cubic phase to ferroelectric tetragonal phase and then to ferroelectric orthorhombic phase and finally to low-temperature rhombohedral phase. 14 The transition from cubic phase to tetragonal at 127°C is important because it is a transition from paraelectrics to ferroelectrics, and the transition temperature is called Curie point. The Curie point can be shifted by the doping of Pb ion to replace Ba to high temperature and by the doping of Sr to low temperature. It is found that the tetragonality, or c / a, of BaTiO 3 based materials at room temperature is related to their Curie point. A larger c / a corresponds to a higher Curie point. Figure 1 shows the ...

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“…There are two ways to reduce the cost of the internal electrode [1]. One is to use base metals as the electrode, such as Ni, Cu.…”

Section: Introductionmentioning

confidence: 99%

“…In order to decrease the sintering temperature, addition of the sintering aids could be an efficient way [1]. Because most of them are non-ferroelectric materials, their doping may "dilute" the ferroelectric properties of the barium titanate: depress the permittivity of the material and raise the dielectric loss.…”

Section: Introductionmentioning

confidence: 99%

The structure and dielectric properties of low temperature sintering barium titanate based x7r ceramics

Wang

Chen

et al. 2007

J Electroceram

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In this paper we try to do systematic investigation on the structure and dielectric properties of low temperature sintered barium titanate based X7R ceramics, which are doped with rare earth oxide, Nb 2 O 5 , Co 3 O 4 using ZnO-B 2 O 3 as the sintering aids. The dielectric ceramic powder can be sintered at the temperature below 950°C to satisfy X7R requirement and also with good permittivity and low dielectric loss. The research strongly suggest that this doped BaTiO 3 based ceramic, which can be sintered at a rather low temperature, may be used in the production of MLCC with low content of Pd in the Ag-Pd electrode, and for sure, the production cost would be greatly reduced.

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Flux Additions in Barium Titanate: Overview and Prospects

Cited by 32 publications

References 21 publications

Low-temperature sintering of Li2O-doped BaTiO3 lead-free piezoelectric ceramics

Low-temperature sintering of Li2O-doped BaTiO3 lead-free piezoelectric ceramics

Dielectric properties of barium titanate ceramics doped by B2O3 vapor

The structure and dielectric properties of low temperature sintering barium titanate based x7r ceramics

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