Preparation and Structural Characterization of CaCu3Ti4O12 Doped with Nickel, Ferrite, Manganese and Cobalt

2014 ◽  
Vol 893 ◽  
pp. 69-74
Author(s):  
Johar Banjuraizah ◽  
Mohd. Haziq Che Ani ◽  
A.R. Mohamed

Transition metal oxide-doped CCTO (CaCu3Ti4O12) ceramics were prepared by a conventional solgel synthesis method and the effects of pure CCTO and CCTO doped with Mn, Fe, Co, Ni to the crystal structure, microstructures and dielectrical properties of samples were investigated. The phase composition and microstructure were studied by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis reveals that all samples exhibited multiphases with the pseudo-perovskite cubic CCTO phase with space group Im-3 as the main phase in undoped and doped CCTO samples. Peaks of monoclinic CuO and peroveskite CaTiO3 could also be seen in all samples which indicate that solid solution of CuO in CaTiO3 lattice was incomplete.SEM results show that doping effectively enhanced densification. SEM micrographs also suggested that the morphologies of doped CCTO ceramics had showed a matrix consisting of large grains wherein the small grains were embedded between the larger grains. Dielectric properties of pure and doped CCTO were investigated in a broad frequency range of the dielectric constant reached a value as high as εr = 29.4 at room temperature for CCTO doped with Ni at frequency (1000 Hz). Besides the sintering conditions, the microstructure and the dielectric properties of the CCTO are strongly influenced by type of doping elements.

2014 ◽  
Vol 625 ◽  
pp. 661-664
Author(s):  
Chen Chuang Lok ◽  
Yin Fong Yeong

In the present work, ZIF-8/6FDA-durene mixed matrix membranes (MMMs) were synthesized and characterized. ZIF-8 nanocrystals, which were used as the inorganic filler, were synthesized using rapid room-temperature synthesis method whereas 6FDA-durene polyimide was synthesized by polycondensation method followed by chemical imidization. Pure and 6FDA-durene membranes loaded with 5 wt%, 10 wt% and 15 wt% of ZIF-8 were fabricated. The structural properties and morphology of the resultant membranes were characterized by using X-ray Diffraction (XRD) and Field emission scanning electron microscope (FESEM) . The EDX images showed that ZIF-8 particles agglomerated in the polymer matrix. However, no phase separation was observed for all resultant MMMs.


2011 ◽  
Vol 324 ◽  
pp. 298-301 ◽  
Author(s):  
Roy Jean Roukos ◽  
Olivier Bidault ◽  
Julien Pansiot ◽  
Ludivine Minier ◽  
Lucien Saviot

Lead free Na0.5Bi0.5TiO3 (NBT) and (Na0.5Bi0.5TiO3)1-x(CaTiO3)x (NBT-CT) piezoelectric ceramics with the perovskite structure were studied. The NBT and NBT-CT samples were synthesized using a solid-state reaction method and characterized with X-ray diffraction (XRD), Raman spectroscopy and dielectric measurements for several compositions (x = 0, 0.07, 0.15) at room temperature. The XRD analysis showed a stabilization of a rhombohedral phase at a low concentration of Ca (0 < x <0.15), whereas Raman spectra reveal a strong modification for the sample with x = 0.15. The dielectric properties of these ceramics were studied by measuring impedance in the 79-451K temperature range for unpoled and field cooling with an electric field (FC) conditions.


2013 ◽  
Vol 664 ◽  
pp. 232-235
Author(s):  
Guo Xian Ma ◽  
Hai Ying Zhang

This study aims to develop a methodology for thermal characterization of APC (air pollution control)fly ash using XRD (X-ray diffraction). It performed XRD analysis as a function of temperature between room temperature and 1200 °C. It is found that major mineralogical components of fly ash involve SiO2, CaCl2, Ca3Si2O7, Ca2SiO4–0.35H2O, Ca9Si6O21–H2O, K2Al2Si2O8–3.8H2O and AlCl3–4Al(OH)3–4H2O. Glass phases account for around 57%, which is conducive to reduction of energy in recycling of the ash. Salts decompose firstly with increase of temperature and then oxides derived from the decomposition process react with SiO2, forming silicates, calcium-silicates and aluminosilicates.


2011 ◽  
Vol 236-238 ◽  
pp. 1893-1896
Author(s):  
De Hui Sun ◽  
Ji Lin Zhang ◽  
De Xin Sun

The magnetic MFe2O4 (M=Co, Ni) nanoparticles are synthesized using a hydrothermal synthesis method in ethylene glycol (EG) solution. Their morphologies, structures, surface properties and magnetism are characterized by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), fourier transform infrared (FTIR) absorption spectra, and vibrating sample magnetometer (VSM), respectively. The nickel ferrite and the cobalt ferrite samples are nearly spherical and homogeneous nanoparticles with average size range of about 90 nm (NiFe2O4) and 30 nm (CoFe2O4). XRD patterns confirm that the NiFe2O4 samples belong to the cubic structure and the CoFe2O4 samples are the rhombohedral structure. The NiFe2O4 nanoparticles are superparamagnetic at room temperature, while the CoFe2O4 nanoparticles are sub-ferromagnetic at room temperature and possess higher saturation magnetization.


2006 ◽  
Vol 518 ◽  
pp. 241-246 ◽  
Author(s):  
S. Marković ◽  
M. Mitrić ◽  
N. Cvjetićanin ◽  
Dragan P. Uskokovic

BaTi1-xSnxO3 (BTS) powders, with x ranging from 0 to 1, were synthesized by solid-state reaction technique. The powders were pressed into pellets and sintered at 1370 and 1420 oC. The structural characterization of sintered BTS samples was made at room temperature using X-ray diffraction and Raman spectroscopy measurements. The BTS samples were found to be singlephase solid solutions. Dielectric properties of sintered BTS samples were studied as a function of sintering temperatures and tin contents, too. For samples with x ranging from 0 up to 0.15, it has been found that the Curie temperature decreases while the maximum of the dielectric constant increases with increasing tin content. These samples have relatively high dielectric constants, contrary to x > 0.2 samples with very low dielectric constants. It is noticed that BTS ceramics sintered at 1420 oC exhibit better dielectric properties than those sintered at 1370 oC.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.


2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 28
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Jean-François Halet ◽  
Sundargopal Ghosh

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.


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