Esca

I. INTRODUCTION Since the discovery of the chemical shift phenomenon and the pioneering work by Siegbahn and co-workers in the mid-1960s,1,2 ESCA (Electron Spectroscopy for Chemical Analysis) has become a powerful tool for chemists and physicists. The technique has been used to study solid state band structure and atomic and molecular bonding in both the solid state and the gas phase. From the point of view of the analytical chemist, however, one of the most important uses of the technique has been in the analysis of solid surfaces. The ESCA technique is essentially nondestructive, universal for all elements except hydrogen, samples a layer less than ∼30Å in depth, and can be applied to any vacuum-worthy solid. Indeed, at this depth resolution, ESCA is the only spectroscopic technique which can be used to study the surfaces of organic systems nondestructively.