Comparison between EDS and EELS
& Periodic Table for EDS and EELS Analysis
- Practical Electron Microscopy and Database -
- An Online Book -

http://www.globalsino.com/EM/  



 

 

=================================================================================

The periodic table in Table 4794a lists the edge-onset energies in EEL spectra and energy peaks in EDS.

Table 4794a. Edge-onset energies in EEL spectra and energy peaks in EDS in the periodic table. The energy levels marked in red are practically detectable by both EDS and EELS methods.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
     
1 H
Hydrogen
EELS: 
K 0.014
  2 He
Helium
EELS: 

K 0.025
                 
3 Li
Lithium
 
 
EELS:  
K 0.055 
 
4 Be
Beryllium
EDS: 
Kα 0.110
EELS: 

K 0.111 
 
  5 B
Boron
EDS
Kα 0.183
EELS: 

L2,3 0.005
K  0.188 
 
6 C
Carbon
EDS
Kα 0.277
EELS: 
L2,3 0.007
K   0.284 
 
7 N
Nitrogen
EDS
Kα 0.392
EELS: 
L2,3 0.009
K   0.399 
 
8 O
Oxygen
EDS
Kα 0.525
EELS: 
L2,3 0.007
L1 0.024
K   0.532
9 F
Fluorine
EDS
Kα 0.677
EELS: 
L2,3 0.009
L1 0.031
K 0.686
10 Ne
Neon
EDS
Kα 0.848
EELS: 

L2,3 0.018
L1 0.045
K 0.867
                 
11 Na
Sodium
EDS: 
Kα 1.041
EELS: 
M1 1  
L2,3 0.031 L1 0.063
K 1.072 
 
12 Mg
Magnesium
EDS: 
Kα 1.253
EELS: 
M1 2
L2,3 0.052
L1 0.089
K 1.305 
 
  Alkali earth     Transition metals     Halogens
  Rare earth     Noble gases     Metalloids
  Non-metals     Alkaline earth     Other metals
13 Al
Aluminium
EDS
Kα 1.486
EELS: 
M1 0.001
L3 0.073
L2 0.074
L1 0.118
K 1.560 
 
14 Si
Silicon
EDS
Kα 1.739
EELS: 
M2,3 0.003
M1 0.008
L3 0.099
L2 0.100
L1 0.149   
K 1.839
15 P
Phosphorus
EDS
Kα 2.013
EELS: 
M2,3 0.010
M1 0.016
L3 0.135
L2 0.136
L1 0.189 
 
16 S
Sulphur
EDS
Kα 2.307
EELS: 
M2,3 0.008
M1 0.016
L3 0.164
L2 0.165
L1 0.229 
 
17 Cl
Chlorine
EDS
Kα 2.621
EELS: 
M2,3 0.007
M1 0.018
L3 0.200
L2 0.202
L1 0.270 
 
18 Ar
Argon
EDS
Kα 2.957 
EELS: 
M2,3 0.012
M1 0.025
L3 0.245
L2 0.247
L1 0.320 
 
                                     
19 K
Potassium
EDS: 
Kα 3.312
   
 
EELS: 
M2,3 0.018
M1 0.034
L3 0.294
L2 
 0.297
L1 0.377
 
 
 
   
 
  
 
20 Ca
Calcium
EDS: 
Kα 3.690
Lα  0.341 
   
EELS: 
M4,5 0.005
M2,3 0.026
M1 0.044
L3 0.347
L2  0.350
L1 0.438
 
 
 
 
   
  21 Sc
Scandium
EDS
Kα 4.088
Lα 0.395 
   
EELS: 
M4,5 0.007
M2,3 0.032
M1 0.054
L3 0.402
L2 0.407
L1  0.500 

 
 
 
   
22 Ti
Titanium
EDS
Kα 4.508
Lα 0.452 
   
EELS: 
M4,5 0.003
M2,3 0.034
M1 0.059
L3 0.455
L2 0.461
L1  0.564 

 
 
 
   
23 V
Vanadium
EDS
Kα 4.949
Lα 0.511 
   
EELS: 
M4,5 0.002
M2,3 0.038
M1 0.066
L3 0.513
L2 0.520

L1  0.628 
 
 
 
   
24 Cr
Chromium
EDS
Kα 5.411
Lα 0.573 
   
EELS: 
M4,5 0.002
M2,3 0.043
M1 0.074
L3 0.575
L2 0.584

L1  0.695 
 
 
 
   
25 Mn
Manganese
EDS
Kα 5.894
Lα 0.637 
   
EELS: 
M4,5 0.004
M2,3 0.049
M1 0.084
L3 0.641
L2 0.652

L1  0.769
 
 
 
 
   
26 Fe
Iron
EDS
Kα 6.398
Lα 0.705 
   
EELS: 
M4,5 0.006
M2,3 0.056
M1 0.095
L3 0.710
L2 0.723

L1  0.846
 
 
    
 
27 Co
Cobalt
EDS
Kα 6.924
Lα 0.776 
   
EELS: 
M4,5 0.003
M2,3 0.060
M1 0.101
L3 0.779
L2 0.794

L1 0.926
 
 
 
 
   
28 Ni
Nickel
EDS
Kα 7.471
Lα 0.851 
   
EELS: 
M4,5 0.004
M2,3 0.068
M1 0.112
L3 0.855
L2 0.872

L1  1.008
 
 
 
 
   
29 Cu
Copper
EDS
Kα 8.040
Lα 0.930 
   
EELS: 
M4,5 0.002
M2,3 0.074
M1 0.120
L3 0.931
L2 0.951

L1 1.096 
 
 
 
   
30 Zn
Zinc
EDS
Kα 8.630
Lα 1.012 
   
EELS: 
M4,5 0.009
M2,3 0.087
M1 0.137
L3 1.021
L2 1.044

L1  1.194
 
 
 
 
   
31 Ga
Gallium
EDS
Kα 9.241
Lα 1.098 
   
EELS: 
N2,3  0.001
M4,5 0.018
M3 0.103
M2 0.107
L3 1.116
L2 1.143

L1  1.298 
 
     
32 Ge
Germanium
EDS
Kα 9.874
Lα 1.188 
   
EELS: 
N2,3  0.003
M4,5 0.029
M3 0.122
M2 0.129
L3 1.217
L2 1.249

L1   1.414 
 
 
    
33 As
Arsenic
EDS
Kα 10.530
Lα 1.282 
   
EELS: 
N2,3  0.003
M4,5 0.041
M3 0.141
M2 0.147
L3 1.323
L2 1.359

L1   1.527 
 
 
    
34 Se
Selenium
EDS
Kα 11.207
Lα 1.379 
   
EELS: 
N2,3  0.006
M4,5 0.057
M3 0.162
M2 0.168
L3 1.436
L2 1.476

L1 1.654 
 
    
35 Br
Bromine
EDS
Kα 11.907
Lα 1.480 
   
EELS: 

N2,3  0.005
N1  0.027
M5 0.069
M4 0.070
M3 0.182
L3 1.551
L2 1.597

L1   1.783
 
36 Kr 
Krypton
EDS:
Kα 12.631 
Lα 1.586
   

EELS: 

N2,3  0.011
N1  0.024
M4,5 0.089
M3 0.214
M2 0.223
L3 1.675
L2 1.727

L1 1.921

   
                                     
37 Rb
Rubidium
EDS: 
Kα 13.373
Lα 1.694
EELS: 

N2,3  0.014
N1 0.030 
M5 0.111
M4 0.112
M3 0.239
L3 1.806
L2 1.865
 
 
38 Sr
Strontium
EDS: 
Kα 14.140
Lα 1.806
EELS: 

N2,3  0.020
N1  0.038
M5 0.133
M4 0.135
M3 0.269
L3 1.941
 
 
 
  39 Y
Yttrium
EDS
Kα 14.931
Lα 1.922
EELS: 

N4,5  0.003
N2,3  0.026
N1  0.046
M5 0.158
M4 0.160
M3 0.301
 
 
 
40 Zr
Zirconium
EDS
Kα 15.744
Lα 2.042
EELS: 

N4,5 0.003
N2,3  0.029
N1  0.052
M5 0.180
M4 0.183
M3 0.331
 
 
 
41 Nb
Niobium
EDS
Kα 16.581
Lα 2.166
EELS: 

N4,5  0.004
N2,3  0.034
N1  0.058
M5 0.205
M4 0.208
M3 0.363
 
 
 
42 Mo
Molybdenum
EDS
Kα 17.441
Lα 2.293
EELS: 

N4,5 0.002
N2,3  0.035
N1  0.062
M5 0.227
M4 0.230
M3 0.393
 
 
 
43 Tc
Technetium
EDS
Kα 18.325
Lα 2.424
EELS: 

N4,5 0.002
N2,3  0.039
N1  0.068
M5 0.253
M4 0.257
M3 0.425
 
 
 
44 Ru
Ruthenium
EDS
Kα 19.233
Lα 2.558
EELS: 

N4,5  0.002
N2,3  0.043
N1  0.075
M5 0.279
M4 0.284
M3 0.461
 
 
 
45 Rh
Rhodium
EDS
Lα 2.696 
  
EELS: 
N4,5 0.003
N2,3  0.048
N1  0.081
M5 0.307
M4 0.312
M3 0.496
 
 
 
46 Pd
Palladium
EDS
Lα 2.838  
  
EELS: 
N4,5 0.001
N2,3 0.051
N1 0.086
M5 0.335
M4 0.340
M3 0.531
 
 
 
47 Ag
Silver
EDS
Lα 2.984 
  
EELS: 
N4,5 0.003
N3 0.056
N2 0.062
M5 0.367
M4 0.373
M3 0.571
 
 
 
48 Cd
Cadmium
EDS
Lα 3.133 
  
EELS: 
O2,3 0.002
N4,5 0.009
N2,3 0.067
N1 0.108
M5 0.404
M4 0.411
M3 0.617
 
 
49 In
Indium
EDS
Lα 3.286
M 0.368
EELS: 

O2,3 0.001
N4,5 0.016
N2,3 0.077
N1 0.122
M5 0.443
M4 0.451

M3 0.664
 
 
50 Sn
Tin
EDS
Lα 3.443
M 0.691
EELS: 

O2,3 0.001
N4,5 0.024
N2,3 0.089
N1 0.137
M5 0.485
M4 0.494
M3 0.715
 
 
51 Sb
Antimony
EDS
Lα 3.604
M 0.733
EELS: 

O2,3 0.002
O1 0.007
N4,5 0.032
N2,3 0.099
N1 0.152
M5 0.528
M4 0.537
M3 0.766
52 Te
Tellurium
EDS
Lα 3.769
M 0.778
EELS: 

O2,3 0.002
O1 0.012
N4,5 0.040
N2,3 0.110
N1 0.168
M5 0.572
M4 0.582
M3 0.819
53 I
Iodine
EDS
Lα 3.937
Kα1 28.615
EELS: 
O2,3 0.003 
O1 0.014
N4,5 0.050
N2,3 0.123
N1 0.186
M5 0.620
M4 0.631
M3 0.875
54 Xe
Xenon
EDS
Lα 4.109
Kα1 29.779
EELS: 

O2,3 0.007
O1 0.018
N4,5 0.063
N2,3 0.147
N1 0.208
M5 0.672
M4 0.685
M3 0.937
                                     
55 Cs
Cesium
EDS: 
Kα 30.971
Lα 4.286 
  
EELS: 
O2,3 0.012
O1 0.023
N5  0.077
N4  0.079
N3  0.162
M5 0.726
M4 0.740
M3 0.998
 
 
56 Ba
Barium
EDS: 
Kα 32.196
Lα 4.465
M 0.972
EELS: 

O3 0.015
O2 0.017
O1 0.040
N5 0.090
N4 0.093
N3 0.180
M5 0.781
M4 0.796
M3 1.063
{57-70}
Lanthanoid
71 Lu
Lutetium
EDS
Lα 7.654
M 1.581 
  
EELS: 
O4,5 0.005
O2,3 0.028
O1 0.057
N6,7 0.007
N5 0.195
N4 0.205
M5 1.588
M4 1.639
 
 
72 Hf
Hafnium
EDS
Lα 7.898
M 1.644 
  
EELS: 
O4,5 0.007
O3 0.031
O2 0.038
N7 0.018
N6 0.019
N5 0.214
M5 1.662
M4 1.716
 
 
73 Ta
Tantalum
EDS
Lα 8.145
M 1.709 
  
EELS: 
O4,5 0.006
O3 0.037
O2 0.045
N7 0.025
N6 0.027
N5 0.230
M5 1.735
M4 1.793
 
 
74 W
Tungsten
EDS
Lα 8.396
M 1.774 
  
EELS: 
O4,5 0.006
O3 0.037
O2 0.047
N7 0.034
N6 0.037
N5 0.246
M5 1.810
M4 1.872
 
 
75 Re
Rhenium
EDS
Lα 8.651
M 1.842 
  
EELS: 
O4,5 0.004
O3 0.035
O2 0.046
N7 0.045
N6 0.047
N5 0.260
M5 1.883
M4 1.949
 
 

76 Os
Osmium
EDS
Lα 8.910
M 1.914 
  
EELS: 
O3 0.046 
O2 0.058
N7 0.050
N6 0.052
N5 0.273
M5 1.960 
 
  
 

77 Ir
Iridium
EDS
Lα 9.174
M 1.977 
  
EELS: 
O4,5 0.004
O3 0.051
O2 0.063
N7 0.060
N6 0.063
N5 0.295
 
 
 
 
 
78 Pt
Platinum
EDS
Lα 9.441
M 2.048 
  
EELS: 
O4,5 0.002
O3 0.051
O2 0.066
N7 0.070
N6 0.074
N5  0.314
 
 
 
 
 
79 Au
Gold
EDS
Lα 9.712
M 2.120 
  
EELS: 
O4,5 0.003
O3 0.054
O2 0.072
N7 0.083
N6 0.087
N5 0.334
 
 
 
 
 
80 Hg
Mercury
EDS
Lα 9.987
M 2.195  
  
EELS: 
O4,5 0.007
O3 0.058
O2 0.081
N7 0.099
N6 0.103
N5 0.360
 
 
 
 
 
81 Tl
Thallium
EDS
Lα 10.267
M 2.267 
  
EELS: 
O5 0.013
O4 0.016
O3 0.076
N7 0.118 
N6 0.122 
N5 0.386
 
 
 
 
 
82 Pb
Lead
EDS
Lα 10.550
M 2.342 
  
EELS: 
P2,3 0.001
P1 0.003
O5 0.020
O4 0.022
O3 0.086
N7 0.138
N6 0.143
N5 0.413
 
 
83 Bi
Bismuth
EDS
Lα 10.837
M 2.419 
  
EELS: 
P2,3 0.003
P1 0.008
O5 0.025
O4 0.027
O3 0.093
N7 0.158
N6 0.163
N5 0.440
 
 
84 Po
Polonium
EDS
Lα 11.129
  
  
EELS: 
P2,3 0.005 
P1 0.012
O4,5 0.031
O3 0.104
O2 0.132
N6,7 0.184
N5 0.473
N4 0.500
 
 
85 At
Astatine
EDS
Lα 11.425 
 
 
EELS: 
P2,3 0.008
P1 0.018
O4,5 0.040
O3 0.115
O2 0.148
N6,7 0.210
N5 0.507
N4 0.533 
 
86 Rn
Radon
EDS
Lα 11.725 
 
 
EELS: 
P2,3 0.011
P1 0.026
O4,5 0.048
O3 0.127
O2 0.164
N6,7 0.238
N5 0.541
N4 0.567
 
 
                         
87 Fr
Francium
EDS: 
Lα 12.029
EELS: 
P2,3 0.015
P1 0.034
O4,5 0.058
O3 0.140
O2 0.182
N6,7 0.268
N5 0.577
N4  0.603
88 Ra
Radium
EDS: 
Lα 12.340
EELS: 

P2,3 0.019
P1 0.044
O4,5 0.068
O3 0.153
O2 0.200
N6,7 0.299
N5 0.603
N4 0.636
[89-102]
Actinoid
103 Lr
Lawrencium
 
104 Rf
Rutherfordium
 
105 Db
Dubnium
 
106 Sg
Seaborgium
 
107 Bh
Bohrium
 
108 Hs
Hassium
 
109 Mt
Meitnerium
 
110 Uun
Ununnilium
 
111 Uuu
Unununium
 
112 Uub
Ununbium
 
  114 Uuq
 
 
 
                               
{lanthanides} {57-70} 57 La
Lanthanum
EDS
Kα 33.441
Lα 4.650
M 0.833
EELS: 
O2,3 0.015
O1 0.033
N4,5 0.099
N3 0.192
N2 0.206
M5 0.832
M4 0.849

M3 1.124
58 Ce
Cerium
EDS
Kα 34.717
Lα 4.839
M 0.883
EELS: 

O2,3 0.020
O1 0.038
N6,7 0.001
N4,5 0.111
N3 0.208
M5 0.884
M4 0.902

M3 1.186
59 Pr
Praseodymium
EDS
Kα 36.031
Lα 5.033
M 0.929
EELS: 

O2,3 0.023
O1 0.038
N6,7 0.002 
N4,5 0.114 
N3 0.218
M5 0.931
M4 0.951

M3 1.243
60 Nd
Neodymium
EDS: 

Kα 37.358
Lα 5.229
M 0.978
EELS: 

O2,3 0.022
O1 0.038
N6,7 0.002
N4,5 0.118
N3 0.225
M5 0.978
M4 1.000

M3 1.298
61 Pm
Prometium
EDS: 

Kα 38.725
Lα 5.432
 
EELS: 

O2,3 0.022 
O1 0.038
N6,7 0.004
N4,5 0.121
N3 0.237
M5 1.027
M4 1.052
M3 1.357
62 Sm
Samarium
EDS:
Lα 5.635
M 1.081 
  
EELS: 

O2,3 0.022
O1 0.039
N6,7 0.007
N4,5 0.130
N3 0.249
M5 1.081
M4 1.107
M3 1.421
63 Eu
Europium
EDS
Lα 5.845
M 1.131 
  
EELS: 
O2,3 0.022
O1 0.032
N4,5 0.134
N3 0.257
M5 1.131
M4 1.161
M3 1.481
 
 
64 Gd
Gadolinium
EDS: 

Lα 6.056
M 1.185 
  
EELS: 
O2,3 0.021
O1 0.036
N4,5 0.141
N3 0.271
M5 1.186
M4 1.218
M3 1.544
 
 
65 Tb
Terbium
EDS
Lα 6.272
M 1.240 
  
EELS: 
O2,3 0.026
O1 0.040
N6,7 0.003
N4,5 0.148
N3 0.286
M5 1.242
M4 1.276
M3 1.612
66 Dy
Dysprosium
EDS
Lα 6.494
M 1.293  
  
EELS: 
O2,3 0.026
O1 0.063
N6,7 0.004
N4,5 0.154
N3 0.293
M5 1.295
M4 1.332
M3 1.676

67 Ho
Holmium
EDS:   
Lα 6.719
M 1.347 
  
EELS: 
O2,3 0.020
O1 0.051
N6,7 0.004
N4,5 0.161
N3 0.306
M5 1.351
M4 1.391
M3 1.741

68 Er
Erbium
EDS:   
Lα 6.947
M 1.405 
  
EELS: 
O2,3 0.029
O1 0.060
N6,7 0.004
N5  0.168
N4  0.177
M5 1.409
M4 1.453
M3 1.812
69 Th
Thulium
EDS:   
Lα 7.179
M 1.462 
  
EELS: 
O2,3 0.032
O1 0.053
N6,7 0.005
N4,5 0.180
N3 0.337
M5 1.468
M4 1.515
M3 1.885
70 Yb
Ytterbium
EDS:   

Lα 7.414
M 1.521 
  
EELS: 
O2,3 0.023
O1 0.053
N6,7 0.006
N5 0.184
N4 0.197
M5 1.527 
M4 1.576
M3 1.949
   
                           
{actinides} [89-102] 89 Ac
Actinium
EDS
Lα 12.650
 
EELS: 
O4,5 0.080
O3 0.167
O2 0.215
N6,7 0.319
N5 0.639
N4 0.675
 
 
   
  
 
90 Th
Thorium
EDS
Lα 12.967
M 2.991
EELS: 

P4,5 0.002
P3 0.043
P2 0.049
O5 0.088
O4 0.095
O3 0.182
N7 0.335
N6 0.344
N5 0.677
91 Pa
Protactinium
EDS
Lα 13.288
M 3.077 
EELS: 

O5,6 0.094
O2,3 0.223
O1 0.310
N7 0.360
N6 0.371
N5 0.708 
 
 
  
 
92 U
Uranium
EDS
Lα 13.612
M 3.164
EELS: 

P4,5 0.004
P3 0.033
P2 0.043
O5 0.096
O4 0.105
O3 0.195
N7 0.381
N6 0.392
N5 0.738
93 Np
Neptunium
EDS
Lα 13.942
M 3.260 
EELS: 

O5 0.101
O4 0.109
O3 0.206
N7 0.404
N6 0.415
N5 0.773
 
 
  
 
94 Pu
Plutonium
EDS
Lα 14.276
M 3.348
EELS: 

O5 0.105
O4 0.116
O3 0.212
N6,7 0.422
N5 0.801
N4 0.849
 
 
  
 
95 Am
Americium
EDS
Lα 14.615
M 3.437
EELS: 

O5 0.103
O4 0.116
O3 0.220
N6,7 0.440
N5 0.828
N4 0.879
 
 
  
 
96 Cm
Curium
EDS
Lα 14.953
M 3.539
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
97 Bk
Berkelium
EDS
Lα 15.304
M 3.634
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
98 Cf
Californium
EDS
Lα 15.652
M 3.731
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
99 Es
Einsteinium
 
 
100 Fm
Fermium
 
 
101 Md
Mendelevium
 
 
102 No
Nobelium
 
 
   
 

Table 4794b lists the comparison between EDS and EELS methods.

Table 4794b. Comparison between EDS and EELS methods.
EDS
EELS
Sensitivity
Better sensitivity: ~0.05 at% (for some elements)
Signal
Lower signal for elements with smaller atomic number
Higher core-loss signal in general
Signal to noise
High: is largely limited by counting statistics (noise is approximately equal to the square root of the signal for thin TEM samples)
Low: is limited by the total signal, including the edge and the underlying background
Acquisition speed
Fast: The total spectrum of interest, from 0.1 keV to the beam energy (e.g., 20 keV) can be acquired in a short time (10 - 100 s).
Slow
Efficiency to atomic number
Less efficient for lighter atoms (say Z < 30), especially not lighter than B.
Better range, but more efficient for lighter atoms
Smaller ionization cross sections
Larger ionization cross sections
Collection efficiency
Background
Lower spectral background
Higher spectral background
Process & transition
X-ray generation can originate from energy loss process of incident electrons. Refer to Figures 4794b and 4794c below.
Energy loss process is the first step after interaction of incident electrons with atoms. Refer to Figures 4794b and 4794c below.
Energy resolution
The typical energy resolution for EDS is of on the order of 120 ~ 150 eV. This is suffcient in most cases for resolving peaks of different elements, but is inadequate for detecting chemical shifts of the atoms which are of the order of a few electronvolts. EDS is thus mainly used for composition analysis.
< 1 eV
Spatial resolution
Beam broadening, so lower: > 2 nm
Higher ultimate spatial resolution: ~ 1 nm
Resolution affected by beam broadening in TEM specimen
Strongly (refer to Figure 4794a below)
Weakly (also refer to Figure 4794a below)
Elements preferred Heavy elements Light elements
Quantification
Standard needed: The relative intensities of the peaks depend on the properties of the detector; Applicable for most cases.
Standardless and absolute quantification: The intensity of EELS signal mostly depends on the TEM specimen but does not depend on the properties of the detector (spectrometer) and the structure of the microscope; therefore, the elemental quantification based on EELS does not require specimen standards. Possible errors.
Data accuracy
Less dependence on crystal orientation: Better (< 1%)
Possible inaccuracy in crystals due to orientation dependence: Poor (±10%)
Structural information (e.g. bonding and structure information)
Not sensitive
Available
Signal (contrast) reversal
The EELS signal becomes smaller than EDS signal when f is greater than fms2. Therefore, the EDS and EELS signals (contrasts) will be reversed between the cases of f < fms1 and f >fms2 (see page1385 and page1386 for details). That is, in the case of f >fms2, higher concentration of an specific element probably does not provide high intensity or contrast in EELS measurements, but it does for EDS.

mass-thickness effects on both EDS and EELS signal (or intensity)

Dependence on EM sample thickness
Signal intensity is a problem from a thin specimen
Signal intensity is better for thin specimen; very thin specimen is needed
Optimized specimen requirement in TEM technique 50-500 nm thick Less than 20-50 nm thick
Applicability Can be conducted on both thick and thin specimens and can be conducted in both SEM and TEM, so that it is most frequently purchased electron microscope accessory for elemental analysis Requires very thin specimens and the analysis is more complicated, so that it is less common. However, the information can be highly valuable
Artefacts
No stray etc.
Operator experience
Less operator intensive; easy and quick.
More operator intensive; need skill.

Figure 4794a shows the schematic illustration of the broadening of electron beam within a thin specimen and of generations of EDS, EELS and AES signals. This beam broadening affects the spatial resolution of EDS significantly, but does not affect those of EELS and AES too much. d, R and Rmax are the spot size , the average diameter, and the maximum diameter of the electron beam within the specimen, respecitively. α and β  are convergence semiangle of the electron beam and the collection semiangle of EELS/EFTEM. The angle-limiting aperture can be the objective aperture of TEM/STEM system or the entrance aperture of the EELS system, which is smaller and dominates the beam intensity arriving at the camera.

schematic illustration of broadening of electron beam within a thin specimen and generation of EDS, EELS and AES signals

Figure 4794a. Schematic illustration of the broadening of electron beam
within a thin specimen and of generations of EDS, EELS and AES signals.

Figure 4794b shows the schematic illustrations of examples of energy loss process of incident electrons (a) and x-ray generation (b). EKE1 and EKE2 represent the kinetic energies of the two generated SEs. ΔE1 and ΔE2 represent the energy losses of the incident electrons after the incident electrons interact with the electrons in the K and L3 subshells, respectively. E1 and E2 are the binding energies of the two electrons. E0 is the energy of the incident electrons in the EMs.

Schematic illustrations of energy loss process (a), x-ray generation (b), and Auger electron generation (c)

Figure 4794b. Schematic illustrations of examples of energy loss process (a) and x-ray generation (b).

Figure 4794c lists the EELS and EDS transitions. Note that the EELS transitions are named by the initial state, while EDS transitions are named by the initial core-hole state, the emission line, and the line strength (1 is the strongest).

EELS and EDS transitions

Figure 4794c. EELS and EDS transitions.

 


 

=================================================================================