The crystal and defect structures of polar KBiNb2O7

2022 ◽  
Author(s):  
Subhadip Mallick ◽  
Weiguo Zhang ◽  
Maria Batuk ◽  
Alexandra Gibbs ◽  
Joke Hadermann ◽  
...  

KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination...

Nanoscale ◽  
2021 ◽  
Author(s):  
Sang-Wook Kim ◽  
Seungmin Baek ◽  
Jin-Soo Ha ◽  
Sungwoo Kim

We firstly synthesized uniform Zn3X2 (X=P, As) quantum dots (QDs) using stable, environmentally friendly zinc precursor instead of organometallic precursor such as Me2Zn or Et2Zn, and controlled the QD size...


2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Tope O. Bolanle-Ojo ◽  
Abiodun D. Joshua ◽  
Opeyemi A. Agbo-Adediran ◽  
Ademola S. Ogundana ◽  
Kayode A. Aiyeyika ◽  
...  

Conducting binary-exchange experiments is a common way to identify cationic preferences of exchangeable phases in soil. Cation exchange reactions and thermodynamic studies of Pb2+/Ca2+, Cd2+/Ca2+, and Zn2+/Ca2+were carried out on three surface (0–30 cm) soil samples from Adamawa and Niger States in Nigeria using the batch method. The physicochemical properties studies of the soils showed that the soils have neutral pH values, low organic matter contents, low exchangeable bases, and low effective cation exchange capacity (mean: 3.27 cmolc kg−1) but relatively high base saturations (≫50%) with an average of 75.9%. The amount of cations sorbed in all cases did not exceed the soils cation exchange capacity (CEC) values, except for Pb sorption in the entisol-AD2 and alfisol-AD3, where the CEC were exceeded at high Pb loading. Calculated selectivity coefficients were greater than unity across a wide range of exchanger phase composition, indicating a preference for these cations over Ca2+. TheKeqvalues obtained in this work were all positive, indicating that the exchange reactions were favoured and equally feasible. These values indicated that the Ca/soil systems were readily converted to the cation/soil system. The thermodynamic parameters calculated for the exchange of these cations were generally low, but values suggest spontaneous reactions.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zeke Liu ◽  
Yaxu Zhong ◽  
Ibrahim Shafei ◽  
Ryan Borman ◽  
Soojin Jeong ◽  
...  

1998 ◽  
Vol 46 (2) ◽  
pp. 215-218 ◽  
Author(s):  
Ronald K. Stoessell

Clay Minerals ◽  
1998 ◽  
Vol 33 (1) ◽  
pp. 35-42 ◽  
Author(s):  
S. Dick ◽  
A. Weiss

AbstractCationic binuclear oxo- and carboxylate bridged Fe(III) complexes of N-alkyl-N,Nbis(2-pyridylmethyl)amines are introduced into the interlayer region of smectites by cation exchange reactions. The reaction can be divided into three steps. After a predominant loading of external surfaces, cation exchange sites at internal surfaces react, accompanied by considerable stmctaral expansion. Both reaction stages belong to the steep section of the exchange isotherms. At a certain loading, which depends on the complex substituents and the layer charge of the smectite, the isotherms become flat. With bulky shaped complex cations and highly charged smectites, exchange is not quantitative; vermiculite-type minerals show a very small complex uptake. For this behaviour, both thermodynamic and kinetic reasons must be considered. From these results the number of cation exchange positions at external surfaces of smectite crystals may be estimated.


2018 ◽  
Vol 30 (10) ◽  
pp. 3265-3275 ◽  
Author(s):  
Manoj Sharma ◽  
Murat Olutas ◽  
Aydan Yeltik ◽  
Yusuf Kelestemur ◽  
Ashma Sharma ◽  
...  

2016 ◽  
Vol 116 (18) ◽  
pp. 10852-10887 ◽  
Author(s):  
Luca De Trizio ◽  
Liberato Manna

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