Structural and Magnetic Characterization of Bi-Substituted Garnet on Si and GaAs

1995 ◽  
Vol 384 ◽  
Author(s):  
Ken M. Ring ◽  
A.L. Shapiro ◽  
F. Deng ◽  
R.S. Goldman ◽  
F. Spada ◽  
...  
Keyword(s):  
Hysteresis Loops ◽  
Film Structure ◽  
X Ray Diffraction ◽  
Plan View ◽  
Transmission Electron ◽  
Potential Applications ◽  
Novel Material ◽  
Sputter Deposited ◽  
20 Nm

ABSTRACTNovel material structures that combine magneto-optic (MO) and semiconductor devices have potential applications in monolithic microwave systems and optoelectronics. We have investigated the materials issues pertaining to the film structure, interface uniformity, and magnetic/MO properties of (BiDy)3(FeGa)5O12 (Bi-DyIG) thin films sputter deposited on Si and GaAs. The rapid thermally annealed films were polycrystalline with a nominal grain size of 20 nm. The magnetic and MO properties were strongly dependent on the type of substrate such that square hysteresis loops and coercivities of 0.1 to 0.9 kOe were observed for Bi-DyIG/Si structures while Bi-DyIG/GaAs structures showed much lower coercivity values (0.03 kOe). A comparison of the magnetic properties, microstructure and substrate composition was carried out with plan-view and cross-section transmission electron microscopy, as well as electron and x-ray diffraction. The results suggest that grain orientation effects, stress, and compositional inhomogeneity due to interfacial reactions or diffusion introduced by the substrate strongly influence the magnetic and MO properties of the films.

Structural Characterization of Heteroepitaxial 3C-SiC

2012 ◽  
Vol 711 ◽  
pp. 27-30 ◽  
Author(s):  
Andrea Severino ◽  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Nicolò Piluso ◽  
Francesco La Via
Keyword(s):  
Growth Rate ◽  
Film Structure ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Transmission Electron ◽  
Crystallographic Defects ◽  
Sic Film ◽  
Sic Films

In this work, we focus our attention on the characterization of 3C-SiC films, grown within a CVD reactor, on Si substrates. It will be shown how the growth procedures influence the SiC film structure and quality with the growth rate used during the growth used as example. Evaluation of crystal structure has been conducted by X-Ray Diffraction (XRD), Raman microscopy and Transmission Electron Microscopy (TEM). Overall film quality increases if films are grown under low growth rate conditions, thanks also to an important reduction in the density of micro-twins. The trend of the full widths at half maximum (FWHMs) of SiC rocking curves, considered good ‘quality indicator’ as their broadenings are affected by crystallographic defects, as a function of 3C-SiC thickness shows a saturated regime for very thick films, due to the saturation of stacking fault density after 50 μm of growth. This work wants to suggest a reasonable path for the characterization of the material structure that can be useful, anywhere and in any time, to assess if the morphology and microstructure of our films are satisfactory and to drive towards the desired improvement.

Magnetic CuFe2O4 Nanoparticles for Adsorpstion of Cr(VI) from Aqueous Solution

2014 ◽  
Vol 896 ◽  
pp. 104-107 ◽  
Author(s):  
Poedji Loekitowati Hariani ◽  
Fahma Riyanti
Keyword(s):  
Aqueous Solution ◽  
Precipitation Method ◽  
Alkaline Condition ◽  
Batch Adsorption ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Adsorption Condition ◽  
Co Precipitation ◽  
20 Nm

CuFe2O4 nanoparticles were synthesized by co-precipitation method from the solution of CuCl2 and FeCl3 in alkaline condition. The prepared magnetic CuFe2O4 can be used to adsorb Cr (VI) ions from aqueous solution and separated from medium by magnetic technique. The characterization of CuFe2O4 with X-Ray diffraction (XRD) showed cubic units shells with diameter in the range 15-20 nm which obtained by Transmission Electron Microscope (TEM). The saturation of magnetization is around 13 emu g-1 measured with Vibrating Sample Magnetometer (VSM). Batch adsorption studies were carried out to optimize adsorption condition. Effective conditions for adsorption of Cr (VI) were found at the weight of CuFe2O4 was 1.0 g with contact time of 60 minutes and pH 3 with adsorption capacity 9.20 mg g-1.

Preparation and Characterization of Biocompatible Magnetic Fluids

2011 ◽  
Vol 338 ◽  
pp. 384-387
Author(s):  
Ye Ji ◽  
Hui Ping Shao ◽  
Zhi Meng Guo ◽  
Dong Hua Yang ◽  
Xiao Ting Liu
Keyword(s):  
Magnetic Fluid ◽  
Magnetic Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
X Ray ◽  
Inverse Spinel Structure ◽  
Transmission Electron ◽  
20 Nm

Nano-Fe3O4magnetic particles were prepared by ultrasonic emulsion method and then were dispersed into water with chitosan or folate as surfactants for biocompatible water-based Fe3O4magnetic fluid. The cubic inverse spinel structure of Fe3O4nanoparticles were analyzed by X-ray diffraction technique (XRD). The saturation magnetizations of different magnetic particles were tested by a vibrating sample magnetometer (VSM). The morphologies of nanoparticles were observed by transmission electron microscope (TEM). The particle size was about uniform 10-20 nm, and their shape was approximately spherical. Meanwhile, dispersity was improved markedly after the surface modification. Comparing to magnetic fluid with chitosan modification, magnetic fluid was coated with chitosan and folate gets higher dispersity and stability when both of them have same saturation magnetizations.

Structural Studies of Sputter-Deposited MoS2 Solid Lubricant Films

1988 ◽  
Vol 140 ◽  
Author(s):  
Michael R. Hilton ◽  
Paul D. Fleischauer
Keyword(s):  
Dark Field ◽  
Film Structure ◽  
Initial Structure ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Preparation Conditions ◽  
Transmission Electron ◽  
Deformation Processes ◽  
Sputter Deposited ◽  
Solid Lubricant Films

AbstractThe relationship between the morphologies and crystal structures of sputter-deposited MoS2 films and their lubricating capabilities is discussed. In particular, aspects of plastic deformation processes are presented. Scanning elecron microscopy (top surface and cross sectional), transmission electron microscopy (lattice imaging and dark field), and x-ray diffraction techniques were used to characterize film structure. The asdeposited morphology, which can be described in terms of zone models, was found to influence the initial nature of the wear debris and the loadbearing capabilities of the films. In many cases a highly deformed region confined to the surface of the films was found. Applied stress was found to reorient crystallites and to induce crystallization, with the degree of both processes being related to the initial structure of the film. Criteria are presented for selecting the film type and preparation conditions to fit various applications.

scholarly journals Synthesis and Characterization of Metal Sulfides Nanoparticles/Poly(methyl methacrylate) Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Peter A. Ajibade ◽  
Johannes Z. Mbese
Keyword(s):  
Electron Microscope ◽  
Methyl Methacrylate ◽  
Metal Sulfides ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Poly Methyl Methacrylate ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
20 Nm

Metal sulfides nanoparticles in poly(methyl methacrylate) matrices were prepared and characterized by infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The FTIR confirms the dispersion of the nanoparticles in PMMA matrices with the C=O and C–O–C bonds of the PMMA shifting slightly which may be attributed to the interactions between the nanoparticles and PMMA. The ZnS nanoparticles in PMMA have average crystallite sizes of 4–7 nm while the CdS has particle size of 10 nm and HgS has crystallite sizes of 8–20 nm. The increasing order of particle sizes as calculated from the XRD is ZnS/PMMA<HgS/PMMA<CdS/PMMA and ranges from 1.02 to 1.35 nm. These calculated particle sizes are smaller than the values obtained from TEM.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

The Effect of the Microstructure of Diffusion Barriers on the Palladium Activation for Electroless Copper Deposition

2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park
Keyword(s):  
Electron Microscopy ◽  
Diffusion Barriers ◽  
Copper Deposition ◽  
X Ray Diffraction ◽  
Plan View ◽  
X Ray ◽  
Transmission Electron ◽  
Electroless Copper ◽  
Sheet Resistance Measurement ◽  
Scanning Electron

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.

scholarly journals (Ti,Al)O2 Whiskers Grown during Glow Discharge Nitriding of Ti-6Al-7Nb Alloy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2658
Author(s):  
Krzysztof Szymkiewicz ◽  
Jerzy Morgiel ◽  
Łukasz Maj ◽  
Małgorzata Pomorska
Keyword(s):  
Surface Hardening ◽  
Surface Defects ◽  
Plasma Nitriding ◽  
Surface Roughening ◽  
Effective Surface ◽  
Plan View ◽  
Gas Nitriding ◽  
Transmission Electron ◽  
Temperature Window ◽  
20 Nm

Plasma nitriding of titanium alloys is capable of effective surface hardening at temperatures significantly lower than gas nitriding, but at a cost of much stronger surface roughening. Especially interesting are treatments performed at the lower end of the temperature window used in such cases, as they are least damaging to highly polished parts. Therefore identifying the most characteristic defects is of high importance. The present work was aimed at identifying the nature of pin-point bumps formed at the glow discharged plasma nitrided Ti-6Al-7Nb alloy using plan-view scanning and cross-section transmission electron microscopy methods. It helped to establish that these main surface defects developed at the treated surface are (Ti,Al)O2 nano-whiskers of diameter from 20 nm to 40 nm, and length up to several hundreds of nanometers. The performed investigation confirmed that the surface imperfection introduced by plasma nitriding at the specified range should be of minor consequences to the mechanical properties of the treated material.

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

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