Spectroscopic and Structural Studies of Some Precursors for the Deposition of PZT and Related Materials by MOCVD

1997 ◽  
Vol 495 ◽  
Author(s):  
Kirsty A. Fleeting ◽  
Tony C. Jones ◽  
Tim Leedham ◽  
M. Azad Malik ◽  
Paul O'brien ◽  
...  

ABSTRACTMOCVD is a useful method for the deposition of thin films of lead zirconium titanate, PZT, because of its good step coverage and control of composition. Results are herein presented on a number of novel compounds which are potential MOCVD precursors. The compounds studied include Pb(tmhd)2, Zr(OBu')4 and Ti(OPr')4. Another commonly utilized precursor Zr(tmhd)4, is not ideal, in that it is a high melting point solid, and hence requires high substrate temperatures. We have sought to modify Zr precursors through chemical methods and have synthesized a number of novel, more volatile, and less intrinsically thermally stable MOCVD precursors. Full chemical characterization of the Zr precursors (NMR, IR, MS, CHN, TGA/DSC, Single Crystal X-ray diffraction) has been undertaken. We also present structural results on some related lead precursors.

1998 ◽  
Vol 541 ◽  
Author(s):  
Hywel O. Davies ◽  
Kirsty A. Fleeting ◽  
Timothy J. Leedham ◽  
Anthony C. Jones ◽  
Paul O'Brien ◽  
...  

AbstractMOCVD is a useful method for the deposition of thin films of metal oxides containing early transition metals, e.g., lead zirconium titanate, (PZT), because of its good step coverage and control of composition. Results are presented on a number of novel compounds which may be, or are, good MOCVD precursors. The compounds studied are in several general classes and include M(←diket)x, M(OR)x, M(←diket)x (OR)y [where M = Ti, Zr, Hf, Ta; ←-diket = tmhd (2,2,6,6-tetramethylheptane-3,5-dione), acac (acetylacetonate), hfac (1,1,1,5,5,5-hexafluoroacetylacetonate); R = Me, Et, Pr1, Butt]. We have sought to modify the precursors through chemical methods and have synthesized a number of novel, volatile, and intrinsically thermally stable MOCVD precursors. Full chemical characterization of the precursors (NMR, IR, MS, CHN, TGA/DSC, Single Crystal X-ray diffraction) has been undertaken.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2160
Author(s):  
Alexander Bogdanov ◽  
Ekaterina Kaneva ◽  
Roman Shendrik

Elpidite belongs to a special group of microporous zirconosilicates, which are of great interest due to their capability to uptake various molecules and ions, e.g., some radioactive species, in their structural voids. The results of a combined electron probe microanalysis and single-crystal X-ray diffraction study of the crystals of elpidite from Burpala (Russia) and Khan-Bogdo (Mongolia) deposits are reported. Some differences in the chemical compositions are observed and substitution at several structural positions within the structure of the compounds are noted. Based on the obtained results, a detailed crystal–chemical characterization of the elpidites under study was carried out. Three different structure models of elpidite were simulated: Na2ZrSi6O15·3H2O (related to the structure of Russian elpidite), partly Ca-replaced Na1.5Ca0.25ZrSi6O15·2.75H2O (close to elpidite from Mongolia), and a hypothetical CaZrSi6O15·2H2O. The vibration spectra of the models were obtained and compared with the experimental one, taken from the literature. The strong influence of water molecule vibrations on the shape of IR spectra of studied structural models of elpidite is discussed in the paper.


2014 ◽  
Vol 805 ◽  
pp. 343-349
Author(s):  
Carine F. Machado ◽  
Weber G. Moravia

This work evaluated the influence of additions of the ceramic shell residue (CSR), from the industries of Lost Wax Casting, in the modulus of elasticity and porosity of concrete. The CSR was ground and underwent a physical, chemical, and microstructural characterization. It was also analyzed, the environmental risk of the residue. In the physical characterization of the residue were analyzed, the surface area, and particle size distribution. In chemical characterization, the material powder was subjected to testing of X-ray fluorescence (XRF). Microstructural characterization was performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The residue was utilized like addition by substitution of cement in concrete in the percentages of 10% and 15% by weight of Portland cement. It was evaluated properties of concrete in the fresh and hardened state, such as compressive strength, modulus of elasticity, absorption of water by total immersion and by capillarity. The results showed that the residue can be used in cement matrix and improve some properties of concrete. Thus, the CSR may contribute to improved sustainability and benefit the construction industry.


Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 459-470
Author(s):  
Mouhssin El Halim ◽  
Lahcen Daoudi ◽  
Meriam El Ouahabi ◽  
Valérie Rousseau ◽  
Catherine Cools ◽  
...  

ABSTRACTTextural, mineralogical and chemical characterization of archaeological ceramics (zellige) from El Badi Palace (Marrakech, Morocco), the main Islamic monument from the Saadian period (sixteenth century), has been performed to enhance restoration and to determine the technology of manufacturing. A multi-analytical approach based on optical and scanning electron microscopy, cathodoluminescence, X-ray fluorescence and X-ray diffraction was used. Re-firing tests on ceramic supports were also performed to determine the firing temperatures used by the Saadian artisans. A calcareous clay raw material was used to manufacture these decorative ceramics. The sherds were fired at a maximum temperature of 800°C in oxidizing atmosphere. The low firing temperature for ‘zellige’ facilitates cutting of the pieces, but also causes fragility in these materials due to the absence of vitreous phases.


2000 ◽  
Vol 611 ◽  
Author(s):  
O. Gluschenkov ◽  
J. Benedict ◽  
L.A. Clevenger ◽  
P. DeHaven ◽  
C. Dziobkowski ◽  
...  

ABSTRACTMaterial interaction during integration of tungsten gate stack for 1 Gb DRAM was investigated by Transition Electron Microscopy (TEM), X-ray Diffraction analysis (XRD) and Auger Electron Spectroscopy (AES). During selective side-wall oxidation tungsten gate conductor undergoes a structural transformation. The transformation results in the reduction of tungsten crystal lattice spacing, re-crystallization of tungsten and/or growth of grains. During a highly selective oxidation process, a relatively small but noticeable amount of oxygen was incorporated into the tungsten layer. The incorporation of oxygen is attributed to the formation of a stable WO x (x<2) composite.


Mining Revue ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 78-82
Author(s):  
Nurudeen Salahudeen ◽  
Aminat Oluwafisayo Abodunrin

Abstract Local clay mineral was mined from Okpella Town, Etsako Local Government Area of Edo State, Nigeria. Mineralogical characterization of the clay was carried out using X-ray diffraction analyzer. Chemical characterization of the clay was carried out using X-ray fluorescence analyzer and the pH analysis of the clay was carried out using pH meter. The mineralogical analysis revealed that the clay was majorly a dolomite mineral having 72% dolomite. The impurities present are 18% cristobalite, 4.1% garnet, 5% calcite and 1% quicklime. The pH analysis of the clay revealed that the clay was acidic having average pH value of 3.9. The pH determined for the 1:1, 1:2, 1:4, 1:8 and 1:10 samples were 3.61, 3.85, 3.85, 4.05 and 4.09, respectively.


1988 ◽  
Vol 140 ◽  
Author(s):  
M. S. Donley ◽  
P. T. Murray ◽  
N. T. McDevitt

AbstractThe growth and characterization of MoS thin films grown by pulsed laser evaporation is investigated. TOF anafysis of the ions evaporated from an MoS2 target indicates that PLE results primarily in the evaporation of atomic Mo and S species; MoxSy clusters were also detected, but were present at a significantly Iower intensity. TOF velocity analysis indicates an effective plasma temperature of 1500K. Stoichiometric MoS2 films were grown at substrate temperatures between room temperature and 500ºC under the above laser conditions. XPS data is used to develop a Wagner chemical state plot. Analysis of the films by Raman spectroscopy and glancing angle x-ray diffraction indicates the films to be crystalline, hexagonal MoS2, with a tendency for basal plane orientation parallel to the substrate.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Le Thi Vinh ◽  
Tran Thu Huong ◽  
Ha Thi Phuong ◽  
Hoang Thi Khuyen ◽  
Nguyen Manh Hung ◽  
...  

We report on the synthesis and characterization of folic acid-conjugated silica-modified TbPO4·H2O nanorods for biomedical applications. The uniform shape TbPO4·H2O nanorods with a hexagonal phase were successfully synthesized by wet chemical methods. A novel TbPO4·H2O@silica-NH2 nanocomplex was then formed by functionalizing these nanorods with silica and conjugating with biological agents. The field emission scanning electron microscopy, energy-dispersive X-ray, and X-ray diffraction reveal the morphology and structure of the nanorods, with their controllable sizes (500-800 nm in length and 50-80 nm in diameter). The Fourier transform infrared spectroscopy was employed to identify chemical substances or functional groups of the TbPO4·H2O@silica-NH2 nanocomplex. The photoluminescence spectra show the four emission lines of TbPO4·H2O@silica-NH2 in folic acid at 488, 540, 585, and 621 nm under 355 nm laser excitation, which could be attributed to the 5D4-7 F j ( J = 6 , 5 , 4 , 3 ) transitions of Tb3+. The TbPO4·H2O@silica-NH2 nanorods were conjugated with folic acid for the detection of MCF7 breast cancer cells. The obtained results show a promising possibility for the recognition of living cells that is of crucial importance in biolabeling.


1997 ◽  
Vol 482 ◽  
Author(s):  
A. D. Serra ◽  
N. P. Magtoto ◽  
D. C. Ingram ◽  
H. H. Richardson

abstractFilms of AlN were grown on MgO(100), Al2O3, and Si under vacuum pressure (10-3 to 10-4 Torr) at different substrate temperatures. They were examined ex situ with infrared reflectance spectroscopy, scanning electron microscopy, x-ray diffraction and rutherford backscattering spectroscopy. Highly oriented smooth films were grown at film thicknesses below 1 μm. Thicker films showed significantly more roughness but remained oriented with respect to the substrate. AIN growth was faster on Si than MgO(100) or Al2O3 and Si was the only substrate that growth was observed at 500°C.


Clay Minerals ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 283-291
Author(s):  
Victor Matheus Joaquim Salgado Campos ◽  
Luiz Carlos Bertolino ◽  
Luana Caroline Silveira Nascimento ◽  
José Yvan Pereira Leite ◽  
Vitor Schwenk Brandão ◽  
...  

AbstractThis research presents the mineralogical and chemical characterization and beneficiation study of two kaolin deposits from the Borborema Pegmatite Province, Brazil. Seven samples were collected and treated in two different beneficiation routes involving magnetic separation and chemical bleaching. The fractions obtained were studied by X-ray diffraction, X-ray fluorescence spectrometry, scanning electron microscopy, particle-size analyses, electron paramagnetic resonance and determination of optical properties. The samples are composed mainly of subhedral kaolinite in the form of booklets, as well as muscovite, quartz, microcline and illite impurities. The kaolinite structural formulae indicated significant replacement of Si4+ by Al3+ in tetrahedral sites and low replacement of Fe3+ by Al3+ in the octahedral sites. The first 30 min of chemical bleaching improved significantly the optical properties of kaolin, indicating that the process is more efficient than magnetic separation.


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