Electronic paramagnetic resonance study of Cu2+ ions in copper ion-exchanged layers of lithium niobate crystals

2001 ◽  
Vol 16 (6) ◽  
pp. 1554-1558 ◽  
Author(s):  
F. Caccavale ◽  
C. Sada ◽  
F. Segato ◽  
L. D. Bogomolova ◽  
V. A. Jachkin ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Crystal Surface ◽  
Exchange Process ◽  
Copper Ion ◽  
Exchange Interactions ◽  
Electronic Paramagnetic Resonance ◽  
Paramagnetic Resonance ◽  
Ion Exchange Process ◽  
Strong Exchange ◽  
Li Ion

Copper-doped LiNbO3 layers prepared by an Cu–Li ion-exchange process are characterized by electronic paramagnetic resonance. It is found that the majority of Cu2+ ions are coupled by strong exchange interactions which is characteristic of short distances between paramagnetic ions. Such ions are accumulated in a thin layer near the crystal surface and can enter in new crystalline phases formed as a result of the Cu–Li ion exchange. A small amount of Cu2+ ions is incorporated into weakly distorted LiNbO3 crystal lattice inside the diffusion layer.

Copper–lithium ion exchange in LiNbO3

2000 ◽  
Vol 15 (5) ◽  
pp. 1120-1124 ◽  
Author(s):  
F. Caccavale ◽  
C. Sada ◽  
F. Segato ◽  
L. D. Bogomolova ◽  
N. A. Krasil'nikova ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Optical Waveguides ◽  
Secondary Ion Mass Spectrometry ◽  
Exchange Process ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Ion Exchange Process ◽  
Optical Modes ◽  
Electron Paramagnetic

Copper-doped LiNbO3 waveguides were prepared by Cu–Li ion-exchange process. Compositional, structural, and optical analyses were performed by secondary ion mass spectrometry, x-ray diffraction, and m-line spectroscopy, respectively. The chemical state of Cu2+ ions was studied by electron paramagnetic resonance, and the results were correlated with structural modification of the LiNbO3 matrix. Copper incorporation in the crystal took place under different regimes, and it induced a lattice rearrangement with the formation of new crystalline phases. Cu2+ ions were surrounded by tetragonally compressed octahedra with rhombic distortions. Cu:LiNbO3 optical waveguides were formed supporting two optical modes.

Preparation of (La, Li)TiO3 Dense Ceramics using Sol-Gel and Ion-Exchange Process

2002 ◽  
Vol 756 ◽  
Author(s):  
Seiichi Suda ◽  
Hiroyuki Ishii ◽  
Kiyoshi Kanamura
Keyword(s):  
Ion Exchange ◽  
Exchange Process ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Exchange Method ◽  
Ion Exchange Process ◽  
Li Ion ◽  
Lithium Ionic Conductor ◽  
Ion Exchange Method ◽  
Water Ratio

ABSTRACTLithium ionic conductor, (La, Li)TiO3, has synthesized with La/Li-TiO2 amorphous spheres that were obtained by sol-gel and ion-exchange method, and succeeding La3+/Li+ partial ion exchange. In this work, La /Li ion exchange conditions were mainly investigated in order to obtain dense (La, Li)TiO3 ceramics that have highly ionic conductivities. La +/Li+ ion exchange behavior was changed with ion-exchange solutions, and the Li/Ti ratio was increased with an increase in ethanol/water ratio in the solvent used for La3+/Li+ partial ion exchange. The use of an adequate ethanol/water ratio resulted in La/Li-TiO2 amorphous spheres with the composition of La/Li/Ti=0.54/0.34/1.00, and sintering of the spheres at 1200°C for 5 h in air led to dense (La, Li)TiO3 ceramics which exhibit the conductivity of 4.0 × 10-3 S cm-1 at 25°C.

Gamma titanium phosphate as an electrode material for Li-ion and Na-ion storage: performance and mechanism

2016 ◽  
Vol 4 (46) ◽  
pp. 18084-18090 ◽  
Author(s):  
Xinghua Xiang ◽  
Xiaocheng Li ◽  
Kongyao Chen ◽  
Yang Tang ◽  
Min Wan ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Low Voltage ◽  
Exchange Process ◽  
Large Radius ◽  
Capacity Retention ◽  
Storage Performance ◽  
Ion Exchange Process ◽  
Ion Storage ◽  
Li Ion ◽  
Performance And Mechanism

Layered G-TiP can store Li+ and Na+ ions via a local ion exchange process and redox reaction. Despite the large radius of Na+, G-TiP exhibits a higher structural tolerance upon (de)sodiation and a better capacity retention at low voltage.

Removal of Toxic Dyestuffs from Aqueous Solution by Amphoteric Bioadsorbent

2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Dye Removal ◽  
Exchange Process ◽  
Cationic Dyes ◽  
Carboxyl Groups ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Isotherm ◽  
Ion Exchange Process ◽  
Dyes And Pigments

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.

Chromate ion-exchange process at alkaline pH

1986 ◽  
Vol 20 (9) ◽  
pp. 1177-1184 ◽  
Author(s):  
Arup K. Sengupta ◽  
Dennis Clifford ◽  
Suresh Subramonian
Keyword(s):  
Ion Exchange ◽  
Exchange Process ◽  
Alkaline Ph ◽  
Ion Exchange Process ◽  
Chromate Ion

The Application of ß“-Alumina As A Solid State Laser Host

1985 ◽  
Vol 60 ◽  
Author(s):  
J. D. Barrie ◽  
D. L. Yang ◽  
B. Dunn ◽  
O. M. Stafsudd
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Ion Exchange ◽  
Exchange Process ◽  
Laser Action ◽  
Solid State Laser ◽  
Host Crystal ◽  
State Laser ◽  
Ion Exchange Process ◽  
Single Host

AbstractIon exchanged ß“-aluminas display a number of interesting optical properties which suggest that the material is well suited for application as a solid state laser host. Small platelets of Nd3+ Ion exchanged β“-alumina exhibit laser action with gain coefficients many times greater than YAG. The versatility of the ion exchange process enables one to form a wide variety of compounds with different active ions and concentrations, thereby allowing the study of many different effects within a single host crystal.

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