Biomedical subjects

K Raghavachari

Publications and source records attributed to K Raghavachari.

11 recordsLinked to original sources

PubMed2002

Hydrogen adsorption on the indium-rich indium phosphide (001) surface: a novel way to produce bridging In-H-In bonds.

The indium phosphide (001) surface provides a unique chemical environment for studying the reactivity of hydrogen toward the electron-deficient group IIIA element, indium. Hydrogen adsorption on the In-rich delta(2 x 4) reconstruction produced a neutral, covalently bound bridging indium hydride. Using vibrational spectroscopy and ab initio cluster calculations, two types of bridging hydrides were identified, a (mu-H)In(2) and a (mu-H)(2)In(3) "butterfly-like" structure. These structures were formed owing to the large thermodynamic driving force for adsorption of H atoms on solid-state indium dimers.

Journal Article↗

PubMed2001

Role of interdimer interactions in NH3 dissociation on si(100)-(2x1).

The dissociation of NH3 on Si(100)-(2x1) is investigated by a combination of infrared absorption spectroscopy and density functional cluster calculations, revealing that this reaction is governed by a complex set of interdimer interactions involving both bare and adsorbate-covered Si dimers. We propose that such adsorbate-induced changes in the electronic structure of neighboring dimers may have general implications for controlling the two-dimensional ordering of reactions on the dimerized Si(100) surface.

Journal Article↗

PubMed2000

New structural model for Si/SiO2 interfaces derived from spherosiloxane clusters: implications for Si 2p photoemission spectroscopy

In this Letter, we investigate the Si/SiO(2) interface structure formed by the chemisorption of H8Si8O12 and other spherosiloxane clusters on Si(100). Using transition state calculations, we clearly demonstrate that the clusters do not bond to the Si(100) surface via single vertex attachment as proposed previously, but rather attach via Si-O bond cleavage. This alternative cracked cluster geometry allows us to predict the photoemission features of spherosiloxane clusters on Si(100) without invoking second nearest neighbor effects.

Journal Article↗

PubMed1995