1 Introduction When the outer electron fills the vacancy left by an ionized electron in the inner shell, the released energy can be passed to another outer electron that causes further emitting of an electron with characteristic energy, this is the basic principle of the Auger electron spectroscopy (AES) [1]. Nowadays, AES is almost an indispensable tool in nanoscience research for its high surface sensitivity (can detect a single atomic layer of 0.1%), quick analysis, small surface damage (can be considered as nondestructive testing), etc [2,3]. As we known, AES has been successfully applied to the identification of surface species by analyzing the peaks’ …show more content…
Also, there exist empirical formulas for J in practice according to Berger & Seltzer, which is illustrated as follows
J⁄Z=0.015 for Z≤13 (2)
J⁄Z=9.76+〖58.5〗^(-0.19) for Z>13 (3)
From the equation(1), the SB becomes negative when E〖(dE/dx)〗_core , 〖(dE/dx)〗_valence=〖(dE/dx)〗_Bethe-〖(dE/dx)〗_core and when 〖(dE/dx)〗_Bethe150eV (20) for gases where E is the electron energy above the Fermi level in eV, a is the monolayer thickness(nm).
3.3 Relative sensitivity factor (RSF) After Shimizu’s discussion about the theoretical quantitative analysis of AES, I still want to refer the universal method for computing the concentration of element i in a matrix which is so-called relative sensitivity factor method[15]. For simplification, the current of detected Auger electrons can be expressed by
I_A=G(1+r) I_p Nλ(1-ω_x )Φ(E_p,E_u ) (20)
Where
G = The instrument factor
Φ(E_p,E_u ) = the ionized probability of electron at E_u by incident electron at E_p
N = the amount of atoms in unit volume
The sensitivity factor is defined as follows
S=(1+r) I_p λ(1-ω_x )Φ(E_p,E_u )