Conduction anisotropy in the Laplace pressure-induced rhombohedral phase of ScSZ ceramics

2013 ◽  
Vol 10 (4) ◽  
pp. 628-630
Author(s):  
Vladimir Barbashov ◽  
Elizaveta Nesova ◽  
Gennady Akimov
Langmuir ◽  
2021 ◽  
Author(s):  
Amir Bayat ◽  
Mahdi Ebrahimi ◽  
Saeed Rahemi Ardekani ◽  
Esmaiel Saievar Iranizad ◽  
Alireza Zaker Moshfegh

1988 ◽  
Vol 71 (1) ◽  
pp. C-34-C-36 ◽  
Author(s):  
Yukishige Kitano ◽  
Yuuji Mori ◽  
Akira Ishitani ◽  
Takaki Masaki
Keyword(s):  

iScience ◽  
2021 ◽  
pp. 102945
Author(s):  
Xiaohuan Wang ◽  
Long Li ◽  
Yingfeng Shao ◽  
Jiachen Wei ◽  
Ruopu Song ◽  
...  
Keyword(s):  

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 702 ◽  
Author(s):  
Juan Matmin ◽  
Irwan Affendi ◽  
Salizatul Ibrahim ◽  
Salasiah Endud

Nanostructured hematite materials for advanced applications are conventionally prepared with the presence of additives, tainting its purity with remnants of copolymer surfactants, active chelating molecules, stabilizing agents, or co-precipitating salts. Thus, preparing nanostructured hematite via additive-free and green synthesis methods remains a huge hurdle. This study presents an environmentally friendly and facile synthesis of spherical nanostructured hematite (Sp-HNP) using rice starch-assisted synthesis. The physicochemical properties of the Sp-HNP were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DR UV-Vis), and nitrogen adsorption–desorption analysis. The Sp-HNP showed a well-crystallized structure of pure rhombohedral phase, having a spherical-shaped morphology from 24 to 48 nm, and a surface area of 20.04 m2/g. Moreover, the Sp-HNP exhibited enhanced photocatalytic degradation of methylene blue dye, owing to the large surface-to-volume ratio. The current work has provided a sustainable synthesis route to produce spherical nanostructured hematite without the use of any hazardous agents or toxic additives, in agreement with the principles of green chemistry for the degradation of dye contaminant.


2005 ◽  
Vol 83 (5) ◽  
pp. 527-540 ◽  
Author(s):  
Duan -Ming Zhang ◽  
Xiang -Yun Han ◽  
Zhi -Hua Li ◽  
Zhi -Cheng Zhong ◽  
Wen -Sheng Yan ◽  
...  

Depending on the lattice distortion, the dielectric properties of PZT and PT ceramics are studied from a structural phase transition point of view. The study involves a more profound physical process than the study of the relation between the dielectric properties and composition x. Two equations connecting the dielectric properties and the lattice distortions are established in the tetragonal and rhombohedral phase regions. In particular, the relation between the dielectric properties and the lattice distortion is investigated in the phase coexistence region of PZT ceramics using a phase statistical distribution model, and we determine the fitting value of the volume fraction of the tetragonal phase VT to composition x in the equation. All the fitting results indicate that our results are very consistent with the related experimental data for PZT and PT ceramics.PACS Nos.: 64.70.–p, 77.22.–d, 77.84.–s


2008 ◽  
Vol 55-57 ◽  
pp. 369-372 ◽  
Author(s):  
T. Sreesattabud ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon

Lead zirconate titanate/tungsten oxide (PZT/WO3) ceramics were prepared from the powders synthesized by a modified triol sol-gel processing method. In this study, the starting materials used for synthesis of PZT-sol were zirconium (IV) propoxide, titanium (IV) isopropxide, lead (II) acetate trihydrate and 1,1,1,- tris (hydroxymethyl) ethane. To prepare PZT/xWO3 powders (where x = 0, 0.5, 1 and 3 wt%), nano-sized WO3 was ultrasonically dispersed and mixed with the PZT sol, dried and calcined at 600°C for 4 h. X-ray diffraction results indicated that fully crystallized powders were obtained. Phase characterization suggested that at high WO3 concentration, the reaction between PZT and WO3 occurred during the calcination process. To prepare PZT/xWO3 ceramics, the powders were pressed and sintered at 1100°C for 6 h. Phase characterization by XRD indicated that the content of WO3 significantly affected tetragonal-to-rhombohedral phase transition. Microstructure of thermally etched samples showed that increasing the content of WO3 decreased grain size of the ceramics.


Author(s):  
Liangbiao Wang ◽  
Dejian Zhao ◽  
Juanjuan Lu ◽  
Weiqiao Liu ◽  
Quanfa Zhou

2014 ◽  
Vol 70 (a1) ◽  
pp. C1522-C1522
Author(s):  
Peter Blanchard ◽  
Brendan Kennedy ◽  
Chris Ling

Significant efforts have been made in the development of (Bi0.5Na0.5)TiO3 ferroelectrics as an alternative to the lead-based industry standard PbTi1-xZrxO3.[1] It has also been shown that doping the A- and B-site of (Bi0.5Na0.5)TiO3 can greatly improve the ferroelectric behavior of these materials,[2] possibly due to the formation of two or more ferroelectric phases at a morphotropic phase boundary (MPB). As such, there is a significant interest in understanding the structural changes in (Bi0.5Na0.5)TiO3-based solid solutions. (Bi0.5Na0.5)TiO3 was originally described as adopting a rhombohedral structure in space group R3c, However, the accuracy of this description has been greatly debated. It was recently suggested that (Bi0.5Na0.5)TiO3 actually adopts a monoclinic structure in space group Cc.[3] Given this recent controversy, we investigated the structural evolution of (Bi0.5Na0.5)TiO3-based solid solutions, particularly the (Bi0.5Na0.5)Ti1-xZrxO3 and (1-x)(Bi0.5Na0.5)TiO3–xBiFeO3 solid solutions., using both diffraction and spectroscopy techniques. Diffraction measurements on (Bi0.5Na0.5)TiO3 confirm that both monoclinic Cc and rhombohedral R3c phases are present at room temperature. Diffraction analysis showed that doping (Bi0.5Na0.5)TiO3 with a small amount of (Bi0.5Na0.5)ZrO3 and BiFeO3 can stabilizes the rhombohedral phase. The Ti/Fe K-edge and Zr L3-edge XANES spectra analysis was performed to determine the effects doping has on the local displacement of the B-site cations.


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