scholarly journals Technology of production of barium-lanthanum cuprate

Author(s):  
S. I. Niftaliev ◽  
L. V. Lygina ◽  
I. V. Kuznetsova ◽  
E. A. Lopatina

With the help of glycine-nitrate technology, nanoparticles of barium-lanthanum cuprate complex oxide were obtained and its properties were studied. According to x-ray phase analysis, the synthesized sample is single-phase.The complex oxide has a perovskite structure with the spatial group Pmmm (47). The parameters of the crystal lattice calculated from the diffractogram are determined. The microstructure of the obtained compositions was determined by scanning electron microscopy. The sample has a porous foam-like microstructure, consists of aggregates having a size of 15-98 nm. Using thermal analysis, it was found that during heating the mass of the sample was lost (4.19%). The greatest loss of mass is observed in the range 318-372 °C, the process is accompanied by an endothermic effect, which corresponds to the loss of bound water, which was sorbed into the pores and entered the structure of the complex oxide. The possibility of the perovskite layered structure to intercalate water and ions into the interlayer space, the structure of which is a "nanoreactor" for further chemical transformations, is confirmed. The enthalpy of deintercolation corresponds to 2.052 kJ/mol, this value correlates with the enthalpy values of deintercolation for perovskite structures (1.5-17.0 kJ/mol). The technology can be applied to solve practical problems of synthesis of nanopowders of mixed oxides as import-substituting components of automotive catalysts and promising ceramic materials with specified functional properties.

2020 ◽  
Vol 116 (20) ◽  
pp. 201905
Author(s):  
Biqiong Yu ◽  
Guichuan Yu ◽  
Jeff Walter ◽  
Vipul Chaturvedi ◽  
Joseph Gotchnik ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
Seung Hyun Park ◽  
Kyung Eon Kim ◽  
Sang Jeen Hong

Coating the inner surfaces of high-powered plasma processing equipment has become crucial for reducing maintenance costs, process drift, and contaminants. The conventionally preferred alumina (Al2O3) coating has been replaced with yttria (Y2O3) due to the long-standing endurance achieved by fluorine-based etching; however, the continuous increase in radio frequency (RF) power necessitates the use of alternative coating materials to reduce process shift in a series of high-powered semiconductor manufacturing environments. In this study, we investigated the fluorine-based etching resistance of atmospheric pressure-sprayed alumina, yttria, yttrium aluminum garnet (YAG), and yttrium oxyfluoride (YOF). The prepared ceramic-coated samples were directly exposed to silicon oxide etching, and the surfaces of the plasma-exposed samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. We found that an ideal coating material must demonstrate high plasma-induced structure distortion by the fluorine atom from the radical. For endurance to fluorine-based plasma exposure, the bonding structure with fluoride was shown to be more effective than oxide-based ceramics. Thus, fluoride-based ceramic materials can be promising candidates for chamber coating materials.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4017
Author(s):  
Dorota Szwagierczak ◽  
Beata Synkiewicz-Musialska ◽  
Jan Kulawik ◽  
Norbert Pałka

New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.


2001 ◽  
Vol 114-116 ◽  
pp. 307-311 ◽  
Author(s):  
José E. Gonçalves ◽  
Sandra C. Castro ◽  
Aline Y. Ramos ◽  
Maria C.M. Alves ◽  
Yoshitaka Gushikem

2008 ◽  
Vol 595-598 ◽  
pp. 897-905
Author(s):  
Eric Caudron ◽  
Régis Cueff ◽  
Christophe Issartel ◽  
N. Karimi ◽  
Frédéric Riffard ◽  
...  

Manganese addition and subsequent yttrium implantation effects on extra low carbon steel were studied by Rutherford Backscattering Spectrometry (RBS), Reflection High Energy Electron Diffraction (RHEED), X-ray Diffraction (XRD) and Glancing Angle X-ray Diffraction (GAXRD). Thermogravimetry and in situ X-Ray Diffraction at 700°C and PO2=0.04 Pa for 24h were used to determine the manganese alloying addition and subsequent yttrium implantation effects on reference steel oxidation resistance at high temperatures. This study clearly shows the combined effect of manganese alloying addition and subsequent yttrium implantation which promotes the formation of several yttrium mixed oxides seem to be responsible for the improved reference steel oxidation resistance at high temperatures.


1986 ◽  
Vol 47 (4) ◽  
pp. 413-416 ◽  
Author(s):  
G. van der Laan ◽  
J.C. fuggle ◽  
M.P. van Dijk ◽  
A.J. Burggraaf ◽  
J.-M. Esteva ◽  
...  

2009 ◽  
Vol 484 (1-2) ◽  
pp. 356-359 ◽  
Author(s):  
Abdelhedi Aydi ◽  
Hamadi Khemakhem ◽  
Annie Simon ◽  
Dominique Michau ◽  
Régnault von der Mühll

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Beata Zielińska ◽  
Ewa Mijowska ◽  
Ryszard J. Kalenczuk

K-Ta mixed oxides photocatalysts have been prepared by impregnation followed by calcination. The influence of the reaction temperature (450°C–900°C) on the phase formation, crystal morphology, and photocatalytic activity in hydrogen generation of the produced materials was investigated. The detailed analysis has revealed that all products exhibit high crystallinity and irregular structure. Moreover, two different crystal structures of potassium tantalates such as KTaO3and K2Ta4O11were obtained. It was also found that the sample composed of KTaO3and traces of unreacted Ta2O5(annealed at 600°C) exhibits the highest activity in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were examined by X-ray diffraction (XRD) and diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic methods, respectively. Morphology and chemical composition of the produced samples were studied using a high-resolution transmission electron microscope (HR-TEM) and an energy dispersive X-ray spectrometer (EDX) as its mode.


2018 ◽  
Vol 156 ◽  
pp. 08015 ◽  
Author(s):  
Muh Amin ◽  
Muhammad Subri

In this study, fabrication and characterization of ceramic membranes preparation was carried out. Porous ceramic membranes were fabricated by extrusion process from different percentage composition of CuZn on (80 wt% Clay, 10 wt% TiO2, 5 wt% Carbon and 5 wt% PVA). The fabricated membranes were sintered at 900°C for 1 hour in an electrical box furnace with heating rate 1oC/min and holding time for 1 hour. Apparent density and porosity were determined by standar methods for ceramic materials. Phase composition of the ceramic support was established by X-Ray Diffraction analysis. SEM studies of the membranes added at different CuZn were carried out.


Sign in / Sign up

Export Citation Format

Share Document