Scanning Electron Microscopy and X-Ray Microanalysis

361 22

Photon energy (keV)

Photon energy (keV)

Si_5keV

Si_4keV

Si_3keV

Si_2.8keV

Si_2.6keV

Si_2.4keV

Si_2.2keV

Si_2.0keV

Si_1.9keV

Si_5keV

Si_4keV

Si_3keV

Si_2.8keV

Si_2.6keV

Si_2.4keV

Si_2.2keV

Si_2.0keV

Si_1.9keV

Counts

100000

Same scale

Same scale

10000

1000

100

10

40000

30000

20000

10000

0

0.0 0.5 1.0 1.5 2.0 2.53.0 3.54.0 4. 55 .0

0.0 0.5 1.0 1.5 2.0 2.53.0 3.54.0 4. 55 .0

Counts

Si

Si

Si

Si

Si

O

C

O

C

Si

5 keV

4 keV

3 keV

2.8 keV

2.6 keV

2.4 keV

2.2 keV

2.0 keV

1.9 keV

. Fig. 22.2 Silicon at various incident beam energies from 5 keV to 1.9 keV showing the decrease in the peak-to-background with decreasing overvoltage

Elemental measurement strategy for conventional beam energy analysis

H He

Li Be BCNOFNe

Na Mg Al Si PSCl Ar

K Ca Sc Ti VCrMnFeCoNiCuZnGaGeAsSeBrKr

Rb Sr YZrNbMoTcRuRhPdAg Cd In Sn Sb Te IXe

Cs Ba La Hf Ta WReOsIrPtAuHgTlPbBiPoAtRn

Fr Ra Ac

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Principal shell used for identification

K-L

L-shell

M-shell

K-shell

L-M

Not detectable

Marginally detectable

EDS resolution: 129 eV (FWHM, MnKα)

U 0 > 1.25 (Ec < 16 keV)

E 0 = 20 keV

. Fig. 22.3 Periodic table
illustrating X-ray shell choices
for developing analysis strategy
within the conventional beam
energy range, E 0 = 20 keV
(Newbury and Ritchie, 2016)

22.1 · What Constitutes “Low” Beam Energy X-Ray Microanalysis?