Scanning Electron Microscopy and X-Ray Microanalysis

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20

quantification suite of elements. A third iteration may be

necessary to recover constituents present at the trace level

near the limits of detection.

20.4.1 Analysis of a Complex Metal Alloy, IN100

IN100

IN100 is a nickel-based superalloy which produces the

EDS spectrum shown in. Fig. 20.9. In the first qualitative

analysis, characteristic X-ray peaks were identified for

Al K; the Ti K-family; the Cr, Co, and Ni K- and L- fami-

lies; and Mo L-family. Analysis with the k-ratio/matrix

correction protocol using pure elements as peak-fitting

references and as standards gave the results shown in

. Table 20.9, with the analytical total slightly below unity.
Close inspection of the residual spectrum in. Fig. 20.9
showed an anomaly at the energy of Ti K-M4,5 (4.931 keV))
which closely corresponds to the energy of V K-L2,3
(4.952  keV) with a separation of 21  eV.  When V
was included in the suite of fitted elements, the anomaly
in the residual spectrum was eliminated, as shown in
. Fig. 20.10, and a minor V constituent was recovered in the
. Table 20.6 Analysis of MoS 2 at E 0 = 10 keV with CuS and Mo
as fitting references and standards; integrated spectrum count,
0.1–10 keV = 7,326,000; uncertainties expressed in mass fraction.
Analysis performed with Mo L2,3-M4,5 and S K-L2,3

S Mo

Cav (atom frac) 0.6644 0.3356

Z-correction 1.039 0.884

A-correction 1.083 1.024

F-correction 1 1

σ (7 replicates) 0.0022 0.0022

σRel (%) 0.33 % 0.66 %

RDEV (%) −0.34 % 0.70 %

C (mass frac, single analysis) 0.3972 0.6046

Counting error, std 0.0003 0.0003

Counting error, unk 0.0006 0.0014

A-factor error 0.0006 0.0006

Z-factor error 2.80×10–5 4.40×10–5

Combined errors 0.0008 0.0015

a 350 000

b

300 000

250 000

200 000

150 000

100 000

50 000

0

1.5 1.7 1.9 2.1 2.3 2.5

Photon energy (keV)

Counts

2.72.9 3.13.3

MoS2_10kV20nA11%DT100s

Residual_MoS2_10kV20nA

MoS2_10kV20nA11%DT100s

20 000 Residual_MoS2_10kV20nA

15 000

10 000

5 000

0

1.5 1.7 1.9 2.1 2.3 2.5

Photon energy (keV)

Counts

2.72.9 3.13.3

E 0 = 10 KeV

MoS 2

Fitting residual

. Fig. 20.6 a SDD-EDS spectrum of MoS 2 (red) at E 0 = 10 keV (7,326,000 counts) and residual (blue) after DTSA II analysis using CuS and Mo as
fitting references and standards. b Expanded view

Chapter 20 · Quantitative Analysis: The SEM/EDS Elemental Microanalysis k-ratio Procedure for Bulk Specimens, Step-by-Step