A NOVEL METHOD FOR DETERMINING ABSOLUTE COVERAGES BY TEMPERATURE-PROGRAMMED DESORPTION WITH APPLICATION TO THE ADSORPTION OF CH3I ON MGO(100)

被引：17

作者：

HOLBERT, VP ^{[1
]}

GARRETT, SJ ^{[1
]}

BRUNS, JC ^{[1
]}

STAIR, PC ^{[1
]}

WEITZ, E ^{[1
]}

机构：

[1] NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208

来源：

SURFACE SCIENCE | 1994年 / 314卷 / 01期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/0039-6028(94)90217-8

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

A new method is presented for conveniently determining the absolute coverage of molecular overlayers on solid surfaces using only temperature programmed desorption (TPD), i.e. no additional measurement techniques must be employed. The method is based on a calibration of the measured mass spectrometer signal during evaporation from multilayers of the adsorbate using an a priori calculation of the evaporation flux. The computation of the evaporation flux requires a knowledge of the molecule's equilibrium vapor pressure at the evaporation temperature and an assumption of near unity trapping/sticking probability for the vapor impinging on the condensed layer at this temperature. The method is illustrated using TPD of methyl iodide from the MgO(100) surface. Significant features in the TPD are discussed in light of the methyl iodide coverages obtained using the method.

引用

页码：107 / 113

页数：7

共 17 条

[1] ADSORPTION, DESORPTION, AND SURFACE-DIFFUSION KINETICS OF NH3 ON MGO(100) [J].