Characterization of adsorbed alkali metal ions in 2:1 type clay minerals from first-principles metadynamics

Ikeda, Takashi; Suzuki, Shinichi; Yaita, Tsuyoshi

Journal of Physical Chemistry A, 119(30), p.8369 - 8375, 2015/07

https://doi.org/10.1021/acs.jpca.5b05934

Adsorption states of alkali metal ions in three kinds of 2:1 type clay minerals are systematically investigated via first-principles-based metadynamics. Our reconstructed free energy surfaces in a two dimensional space of coordination numbers specifically employed as collective variables for describing the interlayer cations show that an inner-sphere (IS) complex is preferentially formed for Cs in the 2:1 type trioctahedral clay minerals with saponitelike compositions, where lighter alkali ions show a tendency to form an outer-sphere one instead. The strong preference for an IS complex observed for Cs is found to result partially from the capability of recognizing selectively Cs ions at basal O atoms with the Lewis basicity significantly enhanced by the isomorphic substitution in tetrahedral sheets.

Proceedings of the 3rd International Symposium on Material Chemistry in Nuclear Environment (MATERIAL CHEMISTRY '02, MC '02); March 13-15, 2002, Tsukuba

MC'02 Sympsoium Committee

JAERI-Conf 2003-001, 451 Pages, 2003/05

JAERI-Conf-2003-001.pdf:30.73MB

The volume contains all presented papers during the the 3rd International Symposium on Material Chemistry in Nuclear Environment: MATERIAL CHEMISTRY '02 (MC'02), held March 13-15, 2002. The purpose of this symposium is to provide an international forum for the discussion of recent progress in the field of materials chemistry in nuclear environments. This symposium intends to build on the success of the previous symposiums held in Tsukuba in 1992 and 1996. The topics discussed in the symposium MC'02 are Chemical Reaction and Thermodynamics, Degradation Phenomena, New Characterization Technology, Fabrication and New Materials, Composite Materials, Surface Modification, and Computational Science.

O reaction dynamics with Si(001) surfaces as observed by synchrotron radiation photoemission spectroscopy

Teraoka, Yuden; Yoshigoe, Akitaka

Atomic Collision Research in Japan, No.28, p.97 - 99, 2002/00

The translational kinetic energy of incident molecules is an important factor for the induction of surface reactions. We applied supersonic seed molecular beam techniques and high-energy-resolution photoemission spectroscopy using synchrotron radiation to the Si initial oxidation analysis. We have already found out that the saturated oxygen coverage on HO-chemisorbed Si(001) surfaces depends on the O incident energy. Two potential energy barriers were confirmed in accordance with the first-principles calculation. An action of the incident energy should be confirmed also on clean Si(001) surfaces. Therefore, the incident energy dependence of the O dissociative chemisorption on the clean Si(001) surface has been investigated by photoemission spectroscopy for Si-2p and O-1s core levels to make clear how the incident energy affects the ultra-thin oxide-layers formation.

Direct numerical algorithm for multiphase flow with free surfaces and interfaces

Kunugi, Tomoaki

Nihon Kikai Gakkai Rombunshu, B, 63(609), p.88 - 96, 1997/05

no abstracts in English