scholarly journals Computer simulation of metal co-doping in lithium niobate

2014 ◽  
Vol 470 (2171) ◽  
pp. 20140406 ◽  
Author(s):  
Romel M. Araujo ◽  
Mário E. G. Valerio ◽  
Robert A. Jackson
Keyword(s):  
Computer Simulation ◽  
Solid State ◽  
Lithium Niobate ◽  
Computer Modelling ◽  
Defect Chemistry ◽  
Experimental Results ◽  
Solid State Reactions ◽  
Co Doping ◽  
Nonlinear Properties ◽  
Electro Optic

Lithium niobate, LiNbO 3 , is an important technological material with good electro-optic, acousto-optic, elasto-optic, piezoelectric and nonlinear properties. Computer modelling provides a useful means of determining the properties of the material, including its defect chemistry, and the effect of doping on the structure. In this work, double-doped LiNbO 3 was studied, and the energetics of the solid-state reactions leading to incorporation of the dopants was calculated. The following combinations of dopants were studied: Fe and Cu; Ce and Cu; Ce and Mn; Fe and Rh; and Ru and Fe. For most of these combinations, the co-doping process decreases the energy required for incorporation of the dopants, and the final defect configurations are consistent with experimental results, where available.

Simultaneous enhancement of photoluminescence and afterglow luminescence through Bi3+ co-doping in the Sr3Al2O5Cl2:Eu2+ phosphor

2018 ◽  
Vol 20 (20) ◽  
pp. 13983-13993 ◽  
Author(s):  
Wei Xie ◽  
Changwei Zou ◽  
Songquan Li ◽  
Jianhui Sun ◽  
Fengwen Kang ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reactions ◽  
Co Doping

In this work, the Sr3Al2O5Cl2:Eu2+ and Sr3Al2O5Cl2:Eu2+,Bi3+ phosphors are synthesized by high temperature solid state reactions.

Mechanisms of solid-state reactions underlying the synthesis of phase-pure lithium niobate

2011 ◽  
Vol 47 (7) ◽  
pp. 768-773 ◽  
Author(s):  
M. N. Palatnikov ◽  
N. V. Sidorov ◽  
V. T. Kalinnikov
Keyword(s):  
Solid State ◽  
Lithium Niobate ◽  
Solid State Reactions ◽  
Phase Pure

Array of Mach Zehnder Modulators for Realization of Parity Generator/Checker

2019 ◽  
Vol 8 (12) ◽  
pp. 2732-2737
Keyword(s):  
Computer Simulation ◽  
Lithium Niobate ◽  
Simulation Model ◽  
Optical Communication ◽  
Optical Switching ◽  
Extinction Ratio ◽  
Power Imbalance ◽  
Switching Device ◽  
Electro Optic ◽  
Parity Generator

The electro-optic effect is one of the most important techniques for modulation and switching purpose in optical communication. The Mach–Zehnder interferometer (MZI) structure functioning on the principle of electro-optic effect behaves as the influential optical switching device. This paper contains discussion of electro-optic effect based MZI structure and its efficient application to construct parity generator and checker. Titanium (Ti) in-diffused lithium niobate profile of MZI through computer simulation has been used for this purpose. Basic 2*2 switch is transformed as MZI for the design of parity device over a functional wavelength range of 1.3 µm to 1.65µm. This simulated design is analyzed with different Ti-LiNbO3 stripe thicknesses, in order to attain the optimum Ti-LiNbO3 stripe thickness and also to improve the performance of the switch on its crosstalk, power imbalance, extinction ratio and transition losses. The simulation model of proposed optical parity device has been implemented using the OptiBPM and OptiSystem softwares have been used for suitable verification of the discussed schemes.

scholarly journals Product Prediction: Intermediates Formed During Rare Earth Reactions

2017 ◽  
Vol 58 (1) ◽  
Author(s):  
Rodrigo Castañeda ◽  
Elizabeth Chavira ◽  
Oscar Peralta
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
High Resolution ◽  
Thermal Behavior ◽  
Thermal Analyses ◽  
Experimental Results ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray

<p>Thermal analyses, X-ray diffraction (XRD), and HR-XRD (High Resolution XRD) were used to identify thermal behavior products in a family of solid-state reactions involving rare earth (REE) reagents. REE where sorted in light and heavy groups. The general reactions under study were: REE<sub>2</sub>O<sub>3</sub> + Fe<sub>2</sub>O<sub>3</sub> + As<sub>2</sub>O<sub>3</sub> → 2REEFeO<sub>3</sub> +<br />As<sub>2</sub>O<sub>3</sub>↑ and 2REE(OH)<sub>3</sub> + Fe<sub>2</sub>O<sub>3</sub> + As<sub>2</sub>O<sub>3</sub> → 2REEFeO<sub>3</sub> + As<sub>2</sub>O<sub>3</sub>↑ + 3H<sub>2</sub>O↑, REE= La, Ce, Nd, Sm, Gd, Dy, Ho, Er, and Yb. Based on the experimental results, it is possible to predict the different compounds of REE products in a series of reactions analyzing only three of the reactions, two for light REE and one for heavy REE.</p>

Microstructural Variations in Melt-Spun Rapidly Solidified Ribbons

1985 ◽  
Vol 43 ◽  
pp. 54-55
Author(s):  
L. A. Bendersky ◽  
W. J. Boettinger
Keyword(s):  
Solid State ◽  
Processing Parameters ◽  
Heat Extraction ◽  
Solid State Reactions ◽  
Careful Examination ◽  
Ion Milling ◽  
Melt Spun ◽  
Wheel Side ◽  
Rapidly Solidified ◽  
Heat Extraction Rate

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

TEM study of amorphization of Cu and Ti foils by cold-rolling

1990 ◽  
Vol 48 (4) ◽  
pp. 146-147
Author(s):  
W. A. Chiou ◽  
N. L. Jeon ◽  
Genbao Xu ◽  
M. Meshii
Keyword(s):  
Solid State ◽  
Cold Rolling ◽  
High Energy ◽  
Rapid Quenching ◽  
Vapor Condensation ◽  
Metallic Alloys ◽  
Solid State Reactions ◽  
High Energy Particle ◽  
Amorphous Metallic Alloys ◽  
Thin Foils

For many years amorphous metallic alloys have been prepared by rapid quenching techniques such as vapor condensation or melt quenching. Recently, solid-state reactions have shown to be an alternative for synthesizing amorphous metallic alloys. While solid-state amorphization by ball milling and high energy particle irradiation have been investigated extensively, the growth of amorphous phase by cold-rolling has been limited. This paper presents a morphological and structural study of amorphization of Cu and Ti foils by rolling.Samples of high purity Cu (99.999%) and Ti (99.99%) foils with a thickness of 0.025 mm were used as starting materials. These thin foils were cut to 5 cm (w) × 10 cm (1), and the surface was cleaned with acetone. A total of twenty alternatively stacked Cu and Ti foils were then rolled. Composite layers following each rolling pass were cleaned with acetone, cut into half and stacked together, and then rolled again.

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

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