Effects of Starting Materials on Molten Salt Synthesis of Bi4Ti3O12

2008 ◽  
Vol 55-57 ◽  
pp. 165-168
Author(s):  
Paisan Setasuwon ◽  
S. Kijamnajsak
Keyword(s):  
Molten Salt ◽  
Grain Growth ◽  
Grain Orientation ◽  
Crystal Size ◽  
Raw Materials ◽  
Piezoelectric Materials ◽  
Molten Salt Synthesis ◽  
Chloride Salt ◽  
Templated Grain Growth

Na0.5Bi0.5TiO3 is one of the potential candidates for non-lead piezoelectric materials to replace existing lead-based ones. Properties of BNT could be enhanced by reactive templated grain growth (RTGG) technique through induction of grain orientation with crystals of Bi4Ti3O12. Controlling the size of Bi4Ti3O12 crystals during the synthesis with molten salt is a major factor in optimizing RTGG. It was found that molten salt synthesis of Bi4Ti3O12 crystals with NaCl-KCl yielded larger particles, compared with Na2SO4-3K2SO4. Varying the proportion of chloride salt did not produce noticeable changes in crystal size. Bi4Ti3O12 crystals were significantly affected by raw materials treatment. Non-milling of starting powders could approximately double the crystal size

Preparation and Characterization of High Textured KSr2Nb5O15 Lead-Free Piezoelectric Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1905-1907
Author(s):  
Li Jin Xie ◽  
Gao Jie Xu ◽  
Zhi Xiang Li
Keyword(s):  
Solid State ◽  
Molten Salt ◽  
Grain Orientation ◽  
Sintered Density ◽  
Raw Materials ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Molten Salt Method ◽  
Templated Grain Growth

Anisometric KSr2Nb5O15 (KSN) particles were synthesized by molten salt method with SrCO3, Nb2O5 and KCl as raw materials. With K2CO3, SrCO3 and Nb2O5 starting materials, KSN lead-free piezoelectric ceramics were prepared by conventional ceramics technique and reactive templated grain growth (RTGG) method, respectively. In the RTGG process, green compacts were fabricated by tapecasting using anisometric KSN as template particles. The KSN particles prepared by molten salt method were rodlike in shape and dense. The KSN ceramics prepared by RTGG not only had higher degree of grain orientation but higher sintered density compared with that prepared by solid-state reaction.

scholarly journals Giant Grain Growth in (K,Na)NbO3 Ceramics

Ceramist ◽  
2021 ◽  
Vol 24 (3) ◽  
pp. 286-294
Author(s):  
Seonhwa Park ◽  
Jung Woo Lee ◽  
Kyung-Hoon Cho ◽  
Yuho Min ◽  
Cheol-Woo Ahn
Keyword(s):  
Single Crystal ◽  
Molten Salt ◽  
Single Crystals ◽  
Grain Growth ◽  
Abnormal Grain Growth ◽  
Molten Salt Synthesis ◽  
Topochemical Reaction ◽  
Templated Grain Growth ◽  
Interesting Phenomenon

In this manuscript, an interesting phenomenon is reported. It has been reported that the growth of single crystals is observed in donor-doped (K,Na)NbO3 (KNN)-based ceramics. It is very interesting that the growth happens without the addition of a seed. The growth of huge grains (single crystal, approximately 30 mm,) occurs due to the abnormal grain growth (AGG) in KNN-based ceramics. In the AGG compositions, moreover, the seed plates can be synthesized by not topochemical reaction but simple molten salt synthesis (SMSS) which is a simple-and-cheap process. They can be a good candidate for the seeds at reactive templated grain growth (RTGG) or templated grain growth (TGG) process.

Fabrication of Textured SrBi2Nb2O9 Ceramics by Templated Grain Growth

2007 ◽  
Vol 26-28 ◽  
pp. 239-242 ◽  
Author(s):  
Chun Wei Cui ◽  
Jin Liang Huang ◽  
Lin Hua Gao ◽  
Xing Hua Yang ◽  
Xiao Wang
Keyword(s):  
Relative Density ◽  
Molten Salt ◽  
Grain Growth ◽  
Grain Orientation ◽  
Sintering Temperature ◽  
Molten Salt Method ◽  
Templated Grain Growth ◽  
Increasing Temperature ◽  
Lotgering Factor ◽  
Peak Value

Textured SrBi2Nb2O9 (SBN) ceramics were fabricated by templated grain growth (TGG) method. The plated-like SBN particles with shape anisotropy prepared by molten salt method were used as the templates. The SBN powders prepared by conventional solid (CS) reaction were used as matrix powders. It was found that the textured SBN ceramics can be obtained by TGG method. The grain orientation (Lotgering factor, f) increased with the increase of sintering temperature and content of the templates. The textured SBN ceramics with f=0.86 could then be obtained after sintering at 1300 °C for 3 h with 20wt.% templates. The relative density keeps rising with increasing temperature until it reaches a peak value 91.22% at the sintering temperature 1300°C, after which it decreases.

Texture Development in Na1/2Bi1/2TiO3-BaTiO3 Ceramics by Reactive-Templated Grain Growth

2007 ◽  
Vol 336-338 ◽  
pp. 121-124
Author(s):  
Yong Ke Yan ◽  
He Ping Zhou ◽  
Wei Zhao ◽  
Dan Liu ◽  
Shan Shan Liu
Keyword(s):  
Molten Salt ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Grain Orientation ◽  
Texture Development ◽  
Molten Salt Method ◽  
Templated Grain Growth ◽  
Important Impact

High <001>-textured Na1/2Bi1/2TiO3-BaTiO3 (6mol%BaTiO3) ceramics were fabricated by reactive-templated grain growth (RTGG), using plate-like Bi4Ti3O14 particles prepared by a molten salt method as the templates. The effect of template concentration on the texture development and microstructure evolution was studied, and the mechanisms of grain orientation and densification were also discussed. The design of Bi element reaction has important impact on the texture development.

scholarly journals Microwave-Assisted Molten-Salt Facile Synthesis of Chromium Carbide (Cr3C2) Coatings on the Diamond Particles

2019 ◽  
Vol 38 (2019) ◽  
pp. 370-379 ◽  
Author(s):  
Lei Xu ◽  
Chenlong Wei ◽  
Wei Li ◽  
Libo Zhang ◽  
Jinhui Peng
Keyword(s):  
Molten Salt ◽  
Chromium Carbide ◽  
Coating Thickness ◽  
Raw Materials ◽  
Heating Temperature ◽  
Molten Salt Synthesis ◽  
Positive Role ◽  
Temperature Range ◽  
Microwave Assisted ◽  
Diamond Particles

AbstractChromium carbide (Cr3C2) coatings on the diamond were fabricated using the mixtures of molten salt of NaCl and BaCl2, powders of metallic chromium and diamond as raw materials in the temperature range of 750–900 °C by the microwave-assisted molten-salt synthesis. The morphology, microstructure and phase composition of the surface layer were characterized by Scanning Electron Microscopy, Energy-dispersive Spectrometry and X-ray diffraction. The results show that the surface of the diamond particles could be coated with Cr, forming a uniform and continuous Cr3C2-coated layer. The coatings thickness on the diamond can be controlled by adjusting the heating temperature and time. The coating thickness expanded from 0.73 to 2.30 µm when the temperature was increased from 750 °C to 900 °C, and increasing rapidly during the temperature range of 800  °C–850  °C, the coating thickness expanded from 1.30 to 2.80 µm when the holding time was increased from 0.5 h to 4 h. The results illustrate that the microwave-assisted molten salt synthesis plays a positive role in chromium coatings on the diamond, offering a potent method for the surface metallization of diamond.

scholarly journals Low-Temperature Molten Salt Synthesis and the Characterisation of Submicron-Sized Al8B4C7 Powder

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 70
Author(s):  
Cheng Liu ◽  
Xueyin Liu ◽  
Zhaoping Hou ◽  
Quanli Jia ◽  
Benjun Cheng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Molten Salt ◽  
Raw Materials ◽  
Reaction Medium ◽  
Thermal Reduction ◽  
Molten Salt Synthesis ◽  
Synthesis Process ◽  
Direct Reaction ◽  
Liquid Reaction ◽  
Reduction Methods

Submicron-sized (~200 nm) aluminium boron carbide (Al8B4C7) particles were synthesised from Al, B4C and carbon black raw materials in a molten NaCl-based salt at a relatively low temperature. The effects of the salt type/assembly and the firing temperature on the synthesis process were examined, and the relevant reaction mechanisms discussed. The molten salt played an important role in the Al8B4C7 formation process. By using a combined salt of 95%NaCl + 5%NaF, an effective liquid reaction medium was formed, greatly facilitating the Al8B4C7 formation. As a result, essentially phase-pure Al8B4C7 was obtained after 6 h of firing at 1250 °C. This temperature was 350–550 °C lower than that required by the conventional direct reaction and thermal reduction methods.

Molten Salt Synthesis of Ni0.5Zn0.5Fe2O4 Ferrites

2012 ◽  
Vol 512-515 ◽  
pp. 1420-1423
Author(s):  
Hong Tao Jiang ◽  
Xiu Feng Wang ◽  
Li Li Wang ◽  
Cheng Long Yu
Keyword(s):  
Molten Salt ◽  
Raw Materials ◽  
Initial Permeability ◽  
Holding Time ◽  
Molten Salt Synthesis ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Text Structures ◽  
Average Grain Size ◽  
Zno Powders

In this paper, Ni0.5Zn0.5Fe2O4ferrite ceramics were produced with Ni0.5Zn0.5Fe2O4powders prepared by reaction in a molten salt using Fe2O3, NiO and ZnO powders as raw materials. Ni-Zn powders were characterized by X-ray diffraction (XRD). Density and shrinkage in diameter of Ni0.5Zn0.5Fe2O4ceramics were measured. MicroSubscript text structures were observed using field emission scanning electron microscopy (FESEM), and magnetic properties were examined by HP4291B impedance analyzer. XRD pattern indicated that the powders synthesized at 900°C for 1h were pure spinel Ni0.5Zn0.5Fe2O4phase. Via the measurement of density and shrink in diameter, optimal temperature was 1200°C and holding time was 2h, which was in accord with the results concluded from micrographs. FESEM images illustrated that the average grain size increased with increasing holding time, which followed the Ostwald liquid growth mechanism. At lower frequencies, the initial permeability (μi) increased from 86.65 to 183.48 with increasing holding time, while the threshold frequency decreased from 13.3MHz to 8.52MHz, which implied the initial permeability (μi) variation complied with the Snoek law to some extent.

Molten salt synthesis of YAG:Ce3+ phosphors from oxide raw materials

2014 ◽  
Vol 40 (3) ◽  
pp. 5067-5071 ◽  
Author(s):  
Lin Gan ◽  
Zhi-Yong Mao ◽  
Fang-Fang Xu ◽  
Ying-Chun Zhu ◽  
Xue-Jian Liu
Keyword(s):  
Molten Salt ◽  
Raw Materials ◽  
Molten Salt Synthesis

SINGLE CRYSTAL GROWTH AND TEXTURING OF LEAD-BASED PIEZOELECTRIC CERAMICS VIA TEMPLATED GRAIN GROWTH PROCESS

2008 ◽  
Vol 01 (02) ◽  
pp. 127-132 ◽  
Author(s):  
THOMAS RICHTER ◽  
CARSTEN SCHUH ◽  
RALF MOOS ◽  
ENDER SUVACI
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystals ◽  
Grain Growth ◽  
High Performance ◽  
Piezoelectric Materials ◽  
Secondary Recrystallization ◽  
Single Crystal Growth ◽  
Templated Grain Growth ◽  
Textured Ceramics

In the field of high-performance piezoelectric materials, PMN-PT single crystals and textured ceramics have been attracting increased research interest for several years. On the other hand, the growth of single crystals from melt for PZT-based compositions is impossible due to its incongruent melting behavior. In order to obtain the characteristics of pure single crystal PZT as closely as possible, the PZT must be textured by secondary recrystallization of introduced seeds in a fine-grained matrix. Zirconium was therefore added to a PMN-PT-ceramic with 32 mol% PT ( Pb ( Mg 1/3 Nb 2/3)0.68 Ti 0.32 O 3) in order to obtain a PMN-PZT-ceramic with 37 mol% PT and 21 mol% PZ ( Pb ( Mg 1/3 Nb 2/3)0.42( Ti 0.638 Zr 0.362)0.58 O 3). Initially, the growth mechanism of (001)-oriented BaTiO 3 (BT) single crystals in those matrices was investigated. The piezoelectric single crystals were produced via a process that starts with the hot pressing of a BT single crystal in cold isostatically pressed ceramics, followed by an additional sintering step in order to achieve a secondary recrystallization. The measured growth lengths in PMN-PT and PMN-PZT matrices were up to 140 μm and 65 μm, respectively. Having developed this understanding, both ceramics were textured via the templated grain growth (TGG) process by using (001)-oriented BT templates. Sintering of templated grain bodies resulted in template growth into the matrix to produce textured ceramics with Lotgering factors up to 0.99 for both compositions. In textured samples unipolar strain s33 was enhanced by a factor of up to 1.8 compared to randomly oriented ceramics. By contrast, BT single crystal growth in an alternative PZT matrix with NdMn doping was not successful. Hence, in the present work, growth experiments in this NdMn -doped PZT were first performed using PZT fibers of similar composition as seeds. Growth of the fiber diameter of up to 100 μm was observed in that matrix.

Microwave dielectric properties of oriented BaLa4Ti4O15 ceramics fabricated by templated grain growth

2004 ◽  
Vol 833 ◽  
Author(s):  
Yuko Fukami ◽  
Kensuke Wada ◽  
Ken-ichi Kakimoto
Keyword(s):  
Dielectric Properties ◽  
Grain Growth ◽  
Microwave Dielectric Properties ◽  
Molten Salt Synthesis ◽  
X Ray Diffraction ◽  
Templated Grain Growth ◽  
Solid State Method ◽  
Microwave Dielectric ◽  
Growth Method ◽  
Large Anisotropy

ABSTRACTDense and highly textured BaLa4Ti4O15 (BLT) ceramics was fabricated by templated grain growth method. Plate-like BLT particles prepared via a molten salt synthesis using NaCl flux were mixed with B LT powders obtained by the conventional solid state method. X-ray diffraction and scanning electron microscope studies of the textured ceramics showed plate-like BLT grains aligned parallel to the casting direction. Large anisotropy was found in the dielectric properties.

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