Lowering Synthesis Temperature of BaTiO3-Bi(Zn0.5Zr0.5)O3 Ceramics by Salt Flux Assistance and Dielectric Properties Investigations

Abstract A rapid and facile approach was developed for the synthesis of ultrafine SmAlO3 powders through the combustion of stearic acid precursors. The obtained products were characterized by typical techniques including X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to analyze the phase composition and microstructure. The dielectric characteristics of SmAlO3 microwave ceramics, using the as-obtained products as original materials, were also studied. Compared with the conventional solid-state reaction method, the synthesis temperature was dramatically reduced to 750 °C. The large-size sheet structure was composed of a number of micro/nano-scale crystallites, which were mostly irregular in shape due to the mutual growth and overlapping shapes of adjacent grains. The SmAlO3 ceramics with high density and uniform microstructure were obtained after sintering at 1500 °C for 4 h due to the favorable sintering activity of the as-synthesized powders. In addition, desired dielectric properties at microwave frequencies (dielectric constant εr = 20.22, quality factor Q·f = 74110 GHz, and a temperature coefficient of resonant frequency τf = −74.6 ppm/°C) were achieved.

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Tuning the Morphology and Electronic Properties of Single-Crystal LiNi0.5Mn1.5O4−δ: Exploring the Influence of LiCl–KCl Molten Salt Flux Composition and Synthesis Temperature

Inorganic Chemistry ◽

10.1021/acs.inorgchem.0c01042 ◽

2020 ◽

Vol 59 (15) ◽

pp. 10591-10603

Author(s):

Stephanie L. Spence ◽

Zhengrui Xu ◽

Sami Sainio ◽

Dennis Nordlund ◽

Feng Lin

Keyword(s):

Single Crystal ◽

Molten Salt ◽

Electronic Properties ◽

Synthesis Temperature ◽

Salt Flux ◽

Flux Composition ◽

Molten Salt Flux

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EFFECT OF THE SYNTHESIS TEMPERATURE ON THE STRUCTURE OF SODIUM-LITHIUM NIOBATE CERAMICS

Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials ◽

10.26456/pcascnn/2020.12.644 ◽

2020 ◽

pp. 644-651

Author(s):

Ольга Витальевна Малышкина ◽

Кирилл Валерьевич Пацуев ◽

Александра Ивановна Иванова

Keyword(s):

Phase Transition ◽

Dielectric Properties ◽

Lithium Niobate ◽

Comparative Study ◽

Piezoelectric Ceramics ◽

Synthesis Temperature ◽

Sodium Niobate ◽

Significant Dependence ◽

Grain Formation

Авторами получены образцы и проведено исследование структуры и диэлектрических свойств пьезоэлектрической керамики на основе ниобатов натрия и лития (LiNa) NbO при различных технологиях синтеза материала ниобата натрия. Проведено сравнительное исследование структуры и диэлектрических свойств полученных образцов. Показана существенная зависимость зернообразования в процессе спекания образцов от температуры синтеза состава NaNbO. Установлено, что температура фазового перехода сильно зависит от температуры первого синтеза ниобата натрия (первый синтез при температуре 650 °С - T ~ 375 °С, при температуре первый синтез 700 °С - Т = 425 °С). The authors synthesized samples and studied the structure of piezoelectric ceramics based on sodium and lithium niobates (LiNa)NbO with various technologies for the synthesis of sodium niobate material. A comparative study of the structure and dielectric properties of the obtained samples was carried out. A significant dependence of grain formation during sintering of the samples on the synthesis temperature of the NaNbO composition is shown. It was found that the temperature of the phase transition strongly depends on the temperature of the first synthesis of the sodium niobate (T ~ 375 °С if the first synthesis temperature was 650 °С; T=425 °С if the first synthesis temperature is 700 °С).

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High Entropy Oxide Phases with Perovskite Structure

Nanomaterials ◽

10.3390/nano10020268 ◽

2020 ◽

Vol 10 (2) ◽

pp. 268 ◽

Cited By ~ 2

Author(s):

Vinnik ◽

Trofimov ◽

Zhivulin ◽

Gudkova ◽

Zaitseva ◽

...

Keyword(s):

Dielectric Properties ◽

Chemical Composition ◽

Perovskite Structure ◽

Single Phase ◽

Synthesis Temperature ◽

Oxide Systems ◽

High Entropy ◽

Solid State Sintering ◽

Oxide Phases ◽

Cubic Structure

The possibility of the formation of high entropy single-phase perovskites using solid-state sintering was investigated. The BaO–SrO–CaO–MgO–PbO–TiO2, BaO–SrO–CaO–MgO–PbO–Fe2O3 and Na2O–K2O–CaO–La2O3–Ce2O3–TiO2 oxide systems were investigated. The optimal synthesis temperature is found between 1150 and 1400 °C, at which the microcrystalline single phase with perovskite structure was produced. The morphology, chemical composition, crystal parameters and dielectric properties were studied and compared with that of pure BaTiO3. According to the EDX data, the single-phase product has a formula of Na0.30K0.07Ca0.24La0.18Ce0.21TiO3 and a cubic structure.

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Chemical synthesis of SmAlO3 by stearic acid route: structure, morphology and microwave dielectric properties

10.21203/rs.3.rs-20935/v1 ◽

2020 ◽

Author(s):

J.M. Li ◽

Chuimin Zhang ◽

Hui Liu ◽

Tai Qiu ◽

Chuangang Fan

Keyword(s):

Electron Microscopy ◽

Dielectric Properties ◽

Stearic Acid ◽

Microwave Dielectric Properties ◽

Solid State Reaction Method ◽

Synthesis Temperature ◽

X Ray Diffraction ◽

Microwave Ceramics ◽

Conventional Solid State Reaction ◽

Microwave Frequencies

Abstract A rapid and facile approach was developed for the synthesis of ultrafine SmAlO3 powders through spontaneously combusting stearic acid precursors. The obtained products were characterized by typical techniques including X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM) and electron microscopy transmission (TEM) to analyze the phase composition and microstructure. The dielectric characteristics of SmAlO3 microwave ceramics using the as-obtained products as original materials were also studied. Comparing with conventional solid-state reaction method, the synthesis temperature was dramatically reduced to 750 °C. Large size sheet structure was composed of a number of micro/nano-scale crystallites that were almost irregular in shape due to the mutual growth and overlapped shape of adjacent grains. The SmAlO3 ceramics with high density and uniform microstructure were obtained after sintering at 1500 °C for 4 h due to good sintering activity of the as-synthesized powders. In addition, desired dielectric properties at microwave frequencies (dielectric constant εr = 20.22, quality factor Q·f = 74110 GHz, and temperature coefficient of resonant frequency TCf = -74.6 ppm/°C) were achieved.

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Preparation and Dielectric Properties of Cr Doped Multiferroic BiFeO3

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.1240 ◽

2012 ◽

Vol 512-515 ◽

pp. 1240-1243 ◽

Cited By ~ 1

Author(s):

Xi Wei Qi ◽

Xiao Yan Zhang ◽

Jian Quan Qi ◽

He Ji Xu ◽

Hai Feng Wang

Keyword(s):

Dielectric Properties ◽

Hydrothermal Method ◽

Frequency Stability ◽

Synthesis Temperature ◽

Grain Structure ◽

Main Peak ◽

Second Phase ◽

Hydrothermal Conditions ◽

Cr Content ◽

Multiferroic Bifeo

A series of Cr doped multiferroic BiFeO3 (BFO) with the composition of BiFe1-xCrxO3 have been prepared using hydrothermal method, in which x varies as 0, 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5. The synthesis temperature is carried out as low as 230 °C under hydrothermal conditions. With the increase of the content of Cr, the second phase is gradually increased. When the value of Cr is 0.5, the main peak (110) and (104) of BFO tends to disappear, in which the structure of BFO is changed. The permittivity of as-prepared samples decreases with the increase of Cr content and excellent frequency stability is exhibited. Better grain structure can be obtained for samples sintered at 830 °C

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Preparation Process of BST Dielectric Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.859.13 ◽

2016 ◽

Vol 859 ◽

pp. 13-17

Author(s):

Li Ping Zhao ◽

Wen Hong Tao ◽

Xing Hua Fu ◽

Wen Zhe Cao ◽

Guo Yuan Cheng ◽

...

Keyword(s):

Dielectric Properties ◽

Room Temperature ◽

Raw Materials ◽

Sol Gel ◽

Synthesis Temperature ◽

Strontium Nitrate ◽

X Ray Diffraction ◽

X Ray ◽

Good Crystallinity ◽

Dielectric Ceramics

Ba0.5Sr0.5TiO3 powders were prepared via a new sol-gel method with titanium oxide, strontium nitrate, and barium nitrate as raw materials. The microstructure and electrical properties were characterized by field scanning electron microscopy, x-ray diffraction and impedance analyser. When the PH = 4, n (CA): n (metal oins) = 3:1 and the synthesis temperature is 800 °C, Ba0.5Sr0.5TiO3 powders were obtained with good crystallinity. BST ceramics sintered at 1250 °C for 2h exhibited good dielectric properties (εr = 930, tanδ = 0.08) at room temperature and f =1 KHz. The relatively low sintering temperature and excellent dielectric properties would make these ceramics promising for applications in electronics.

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