Novel Precursors for MOCVD of Thin Films of Metal Oxides Containing Early Transition Metals

1998 ◽  
Vol 541 ◽  
Author(s):  
Hywel O. Davies ◽  
Kirsty A. Fleeting ◽  
Timothy J. Leedham ◽  
Anthony C. Jones ◽  
Paul O'Brien ◽  
...  
Keyword(s):  
Thin Films ◽  
Transition Metals ◽  
Metal Oxides ◽  
Chemical Characterization ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
Mocvd Precursors ◽  
And Control ◽  
Early Transition

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.

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 ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Lead Zirconium Titanate ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
Chemical Methods ◽  
X Ray ◽  
Mocvd Precursors ◽  
And Control ◽  
Substrate Temperatures

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.

scholarly journals New Insights into the Crystal Chemistry of Elpidite, Na2Zr[Si6O15]·3H2O and (Na1+YCax□1−X−Y)Σ=2Zr[Si6O15]·(3−X)H2O, and Ab Initio Modeling of IR Spectra

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2160
Author(s):  
Alexander Bogdanov ◽  
Ekaterina Kaneva ◽  
Roman Shendrik
Keyword(s):  
Ir Spectra ◽  
Structural Models ◽  
Chemical Characterization ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Special Group ◽  
X Ray ◽  
Influence Of Water ◽  
Radioactive Species

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.

Processing by Pulsed Laser Deposition and Structural, Morphological and Chemical Characterization of Bi-Pb-Sr-Ca-Cu-O and Bi-Pb-Sb-Sr-Ca-Cu-O Thin Films

2010 ◽  
Vol 75 ◽  
pp. 202-207
Author(s):  
Victor Ríos ◽  
Elvia Díaz-Valdés ◽  
Jorge Ricardo Aguilar ◽  
T.G. Kryshtab ◽  
Ciro Falcony
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Chemical Characterization ◽  
Laser Deposition ◽  
Nominal Composition ◽  
Deposition Parameters ◽  
The Relationship

Bi-Pb-Sr-Ca-Cu-O (BPSCCO) and Bi-Pb-Sb-Sr-Ca-Cu-O (BPSSCCO) thin films were grown on MgO single crystal substrates by pulsed laser deposition. The deposition was carried out at room temperature during 90 minutes. A Nd:YAG excimer laser ( = 355 nm) with a 2 J/pulse energy density operated at 30 Hz was used. The distance between the target and substrate was kept constant at 4,5 cm. Nominal composition of the targets was Bi1,6Pb0,4Sr2Ca2Cu3O and Bi1,6Pb0,4Sb0,1Sr2Ca2Cu3OSuperconducting targets were prepared following a state solid reaction. As-grown films were annealed at different conditions. As-grown and annealed films were characterized by XRD, FTIR, and SEM. The films were prepared applying an experimental design. The relationship among deposition parameters and their effect on the formation of superconducting Bi-system crystalline phases was studied.

Influence of the Residue of Casting by Lost Wax in the Modulus of Elasticity and Porosity of Concretes

2014 ◽  
Vol 805 ◽  
pp. 343-349
Author(s):  
Carine F. Machado ◽  
Weber G. Moravia
Keyword(s):  
Construction Industry ◽  
Modulus Of Elasticity ◽  
Chemical Characterization ◽  
Microstructural Characterization ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardened State ◽  
Material Powder

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.

Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Band ◽  
Sol Gel ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Gel Technique ◽  
High Degree ◽  
First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

The Ferroelectric and Electrical Properties of CaBi4Ti4O15 Thin Films Prepared by Sol-Gel Technology

2011 ◽  
Vol 239-242 ◽  
pp. 891-894 ◽  
Author(s):  
Tsung Fu Chien ◽  
Jen Hwan Tsai ◽  
Kai Huang Chen ◽  
Chien Min Cheng ◽  
Chia Lin Wu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Sol Gel ◽  
Morphological Characterization ◽  
Experimental Result ◽  
X Ray Diffraction ◽  
Solution Deposition ◽  
Capacitance Voltage ◽  
Preferential Crystal Orientation

In this study, thin films of CaBi4Ti4O15with preferential crystal orientation were prepared by the chemical solution deposition (CSD) technique on a SiO2/Si substrate. The films consisted of a crystalline phase of bismuth-layer-structured dielectric. The as-deposited CaBi4Ti4O15thin films were crystallized in a conventional furnace annealing (RTA) under the temperature of 700 to 800°C for 1min. Structural and morphological characterization of the CBT thin films were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The impedance analyzer HP4294A and HP4156C semiconductor parameters analyzer were used to measurement capacitance voltage (C-V) characteristics and leakage current density of electric field (J-E) characteristics by metal-ferroelectric-insulator- semiconductor (MFIS) structure. By the experimental result the CBT thin film in electrical field 20V, annealing temperature in 750°C the CBT thin film leaks the electric current is 1.88x10-7A/cm2and the memory window is 1.2V. In addition, we found the strongest (119) peak of as-deposited thin films as the annealed temperature of 750°C

Structural and Optical Characterization of Zinc Telluride Thin Films

2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak
Keyword(s):  
Thin Films ◽  
Extinction Coefficient ◽  
Nir Spectroscopy ◽  
Optical Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Evaporation Technique ◽  
Film Form ◽  
Znte Thin Films

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.

scholarly journals Characterization of superconducting oxide thin films by X-ray diffraction.

1990 ◽  
Vol 37 (1) ◽  
pp. 141-144
Author(s):  
Tsunekazu Iwata ◽  
Akihiko Yamaji ◽  
Youichi Enomoto
Keyword(s):  
Thin Films ◽  
X Ray Diffraction ◽  
Oxide Thin Films ◽  
X Ray
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