Controllable synthesis of pure monodispersed zirconia nanopowders with tetragonal phase

2020 ◽  
Author(s):  
Weiyan He ◽  
Xia Guo ◽  
Xiaobing Zhao ◽  
Jinrong Liu
Keyword(s):  
Tetragonal Phase ◽  
Controllable Synthesis ◽  
Zirconia Nanopowders

Effects of Calcium Oxide and Magnesium Oxide Stabilizing Agents on the Critical Transformation Size of Tetragonal Zirconia

2020 ◽  
Vol 980 ◽  
pp. 15-24
Author(s):  
Liang Zhao ◽  
Shuang Yao ◽  
Yong Qiang Li ◽  
Zhi Long Zhao ◽  
Qun Hu Xue
Keyword(s):  
Particle Size ◽  
Magnesium Oxide ◽  
Calcium Oxide ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Tetragonal Zirconia ◽  
Phase Content ◽  
Stabilized Zirconia ◽  
Stabilizing Agents ◽  
Zirconia Nanopowders

The preparation of tetragonal zirconia nanopowders by sol–gel method using zirconium oxychloride as raw material, ammonia water and sodium hydroxide solution as precipitant, and calcium oxide or magnesium oxide powders as stabilizing agents is described. After suction filtration, drying, and calcination, tetragonal zirconia nanopowders with different particle size and tetragonal phase content were obtained. The particle size and phase composition of the powders are characterized by using a laser particle size analyzer and an X-ray diffractometer, and the tetragonal phase content and grain size are calculated from the crystal plane formula and Scherrer formula. The analysis of the relationship between the tetragonal phase content and the particle size of the zirconia nanopowders stabilized by calcium oxide and magnesium oxide at room temperature reveals the inhibitory effect of the stabilizing agents on the growth of zirconia grains. The stabilized zirconia nanopowder is finer than unstabilized zirconia nanopowder, and the particle distribution is more uniform in the former. The stabilizing effect of calcium oxide is superior to that of magnesium oxide; the critical transformation size of the zirconia grains stabilized by calcium oxide is the largest, and that of unstabilized zirconia is the smallest. The critical transformation size of calcium oxide-stabilized, magnesium oxide-stabilized, and unstabilized zirconia nanopowders is 18–22.6 nm, 24–28 nm, and 26–33.6 nm, respectively. Under the same calcination condition, the calcium oxide-stabilized zirconia nanopowder retains the highest tetragonal phase content at room temperature.

Ferroelectric Domain Structure of Pb(Zr.52Ti.48)03

1980 ◽  
Vol 38 ◽  
pp. 214-215
Author(s):  
E.K. Goo ◽  
R.K. Mishra
Keyword(s):  
Phase Transformation ◽  
Domain Structure ◽  
Tetragonal Phase ◽  
Ferroelectric Domain ◽  
Cubic Phase ◽  
Ion Milling ◽  
Thin Foils ◽  
Ferroelectric Domain Structure ◽  
Ferroelectric Domains

Ferroelectric domains are twins that are formed when PZT undergoes a phase transformation from a non-ferroelectric cubic phase to a ferroelectric tetragonal phase upon cooling below ∼375°C.,1 The tetragonal phase is spontaneously polarized in the direction of c-axis, making each twin a ferroelectric domain. Thin foils of polycrystalline Pb (Zr.52Ti.48)03 were made by ion milling and observed in the Philips EM301 with a double tilt stage.

Shape controllable synthesis of NdFeO3micro single crystals by a hydrothermal route

CrystEngComm ◽  
2014 ◽  
Vol 16 (5) ◽  
pp. 858-862 ◽  
Author(s):  
You Wang ◽  
Xuecheng Yan ◽  
Jun Chen ◽  
Jinxia Deng ◽  
Ranbo Yu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Controllable Synthesis ◽  
Hydrothermal Route

Phase transformation and preferred orientation in carboxylate derived ZrO2 thin films on silicon substates

1992 ◽  
Vol 7 (11) ◽  
pp. 3065-3071 ◽  
Author(s):  
Peir-Yung Chu ◽  
Isabelle Campion ◽  
Relva C. Buchanan
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Phase Transformation ◽  
Heating Rate ◽  
Tetragonal Phase ◽  
Monoclinic Phase ◽  
Preferred Orientation ◽  
Si Substrate ◽  
Interfacial Diffusion ◽  
Deposited Films

Phase transformation and preferred orientation in ZrO2 thin films, deposited on Si(111) and Si(100) substrates, and prepared by heat treatment from carboxylate solution precursors were investigated. The deposited films were amorphous below 450 °C, transforming gradually to the tetragonal and monoclinic phases on heating. The monoclinic phase developed from the tetragonal phase displacively, and exhibited a strong (111) preferred orientation at temperature as low as 550 °C. The degree of preferred orientation and the tetragonal-to-monoclinic phase transformation were controlled by heating rate, soak temperature, and time. Interfacial diffusion into the film from the Si substrate was negligible at 700 °C and became significant only at 900 °C, but for films thicker than 0.5 μm, overall preferred orientation exceeded 90%.

Morphology and composition controllable synthesis of Mg–Al–CO3 hydrotalcites by tuning the synthesis pH and the CO2 capture capacity

2012 ◽  
Vol 55 ◽  
pp. 18-26 ◽  
Author(s):  
Qiang Wang ◽  
Hui Huang Tay ◽  
Zhanhu Guo ◽  
Luwei Chen ◽  
Yan Liu ◽  
...  
Keyword(s):  
Co2 Capture ◽  
Controllable Synthesis ◽  
Co2 Capture Capacity ◽  
Capture Capacity

Controllable synthesis of SAPO-11/5 intergrowth zeolite for hydroisomerization of n-hexane

2021 ◽  
Vol 313 ◽  
pp. 110857
Author(s):  
Ye Yang ◽  
Lu Xu ◽  
Yuchao Lyu ◽  
Xinmei Liu ◽  
Zifeng Yan
Keyword(s):  
Controllable Synthesis
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