Surface and Bulk Plasmon Energy in EELS
- Practical Electron Microscopy and Database -
- An Online Book -

http://www.globalsino.com/EM/  



 

This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.

 

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

The surface and bulk plasmon energies in EELS can be theoretically modeled. Here, Table 4623 lists bulk plasmon energies, full-width-at-half-maximum of bulk plasmon energies, bulk plasmon mean free path, and inelastic mean free path of some common elements and compounds, as well as their crystal structure (Notation: a for amorphous, b for body-centered cubic, c for cubic, f for face-centered cubic, h for hexagonal, l for liquid, o for orthorhombic, r for rhombohedral, t for tetragonal) [1 -  6].The bulk plasmon mean free path λp represents the collective valence electron component of inelastic scattering. The differences between λp and λi reflect single-electron excitation, for example, an inner-shell ionization edge occurring below 150 eV. In addition, Table 4623 also lists surface plasmon energies (Es) of some elements and components. Note that the accuracies are ~5%–10% for λ and ~10%–30% for λp. [16]
Table 4623. Surface plasmon energies (Es), bulk plasmon energies (Ep in eV), full width at half-maximum EpEp), bulk plasmon mean free path (λp in nm), approximate bulk plasmon mean free path obtained by theoretical calculation (λapp in nm), and inelastic mean free path (λi in nm) at different incident kinetic energies (λi3, λi30, λi100, λi200, and λi300 at incident kinetic energies of 3 keV, 30 keV, 100 keV, 200 keV, and 300 keV, respectively). Note: for some elements, the table lists multiple values gathered from different references.
Materials
Es , eV
ΔEp, eV
Ep, eV
<100 keV
λi100, nm
λi200, nm
λi300, nm
λapp, nm
λp, nm**
Ag (f)
3.7
25
100
125
Ag2O
112
Al
10.3[7,8]
15.3[7,8]
λi30=55.5
107.5
134
155
160
AlAs
16.1
146
Al2O3 (α)
10 - 20
22.2-26[9-12]
130-140
109
As (r)
18.7
129
As (a)
16.7
142
Au (Gold)
λi30=38
67
Au (f)
~1
24.8
84
120
B(a)
18
22.7
123
110
126
Ba (b)
7.5
27.8
94
BaO
27.6
125
Be(h)
4.8
18.7
160
129
169
Bi (r)
6.5
14.2
105
162
147
Bi2O3
125
BN (h)
9 & 26
BN (a)
24
106
B2O3
120
C
λi30=67
133
C (diamond)
13
33.2
112
81
116
C (graphite)
7 & 27
C (a)
20
24
160
106
Ca (f)
2.1
8.8
241
CaO
130
Cd (h)
107
130
Ce2O3
125
Co (h)
20.9
98
118
108
CoO
24.6
115
Cr (b)
24.9
104
102
149
Cr2O3
118
Cs (b)
2.9
175
Cu (Copper)
λi30=46.4
87
Cu (f)
19.3
100
126
100
Dy (h)
118
310
Dy2O3
126
Er (h)
14
Er2O3
115
Eu2O3
118
Fe (b)
23
102
109
121
Fe2O3
21.8
116
Ga
0.6
13.8
166
GaAs
15.8
148
GaN
19.4
GaP
16.5
143
GaSb
13.3
171
Ge
λi30=~ 20
Ge (c)
15.8
120-140
148
126
GeO2
130
Gd (h)
110
275
Gd2O3
14.6
125
158
Hf (h)
95
237
~112
Hg (l)
1
6.4
HgO
116
Ho2O3
120
I (o)
140
233
In (t)
12
11.4
110
129
Ir (b)
78
121
IrO2
29
110
La2O3
130
Li (b)
2.2
7.1
289
LiH
20.9
118
LiF
24.6
103
Mg (h)
0.7
10.3
150
211
214
MgB2
18.9
MgF2
24.6
103
MgO
22.3
93
133
152
112
Mn (c)
21.6
106
115
146
Mo (b)
25.2
98
163
MoO3
24.4
111
Na (b)
0.4
5.7
348
NaCl
15.5
151
Nb (b)
105
194
NbC
    24.0            
Nd2O3
14.2
120
162
Ni (f)
20.7
98
119
103
NiO
22.6
115
111
NiSi2
19.75 - 20.0
NiSi
20.25 - 20.7
Ni2Si
21.9
NiTi alloy
100
P (o)
160
160
Pb (f)
13
99
141
PbO
122
Pd (b)
6.5[13]
25.1&31.9[13]
94
118
PdO
3.7&7.6[13]
110
Pr2O3
122
Pt (b)
22.6
82
111
120
Rb (b)
0.6
3.41
539
Re (h)
28
78
141
Ru (b)
90
134
S (o)
200
200
Sb (r)
3.3
15.2
120
145
234
Sc (h)
14
604
Sc2O3
125
Se (h)
6.2
17.1
130
205
Se (a)
6.2
16.3
145
SeO2
3.95
130
Si (Silicon)
λi3< 5; λi30=~ 20
97
147
180
Si (c)
8.2
3.2
16.7
121
145
142
168
Si (a)
3.9
16.3
145
SiC (α)
3.9
21.5
Si3N4 (α)
10.1
23.7
SiO2 (α)
16.6
22.4
155
112
SiO2
102
178
247
Sm (r)
112
280
Sm2O3
13.5
120
Sn (t)
10
1.3
13.7
0.7[100 eV], 1.0[200 eV]; 1.4[400 eV], 1.6[600 eV][14]
115
167
273
SnO
1.0[100 eV], 1.4[200 eV]; 1.9[400 eV], 2.3[600 eV][14]
SnO2
1.0[100 eV], 1.4[200 eV]; 1.9[400 eV], 2.3[600 eV][14]
115
Sr (b)
2.3
8
261
SrO
32
126
SrTiO3
115[15]
Ta (b)
88
183
TaC
    22.4            
Tb (h)
13.3
Tb2O3
125
Te (h)
6.2
17.1
130
216
Ti (h)
17.9
120
134
202
~140
   
TiO
120
Tl (h)
95
135
V (b)
21.8
109
114
158
Vacuum***
50 meters
VC
    22.2            
V2O5
116
W (b)
82
151
WO3
110
Y (h)
7
12.5
124
354
Yb (f)
110
275
Yb2O3
115
YH2
15.3
Y2O3
5.01
122
Zn (h)
17.2
106
138
106
ZnO
16                
Zr (h)
113
268
ZrO2
115

* λi presents the inelastic mean free paths at uncommon accelerating voltages of the electron beam. The applied voltages are noted by [].
** λp gives an approximate value of the bulk plasmon mean free path (which is normally equal to an approximate inelastic mean free path).
*** Vacuum of 10-4 Torr (10100 air molecules/cm3).

In the applications of material science and engineering, the incident electron beam in TEMs used for EELS analysis is normally accelerated to 200 keV. Therefore, the bulk plasmon mean free path (λi200) at such incident kinetic energies is generally in the range of ~80 and 200 nm. Figure 4623 shows a clear periodic dependence of λi200 such that within one row of the Periodic Table, the minimum (maximum) of λi200 is observed for the elements with completed (empty) outer d shell. The oxides present a smaller variation. For oxides, the atomic number Z corresponds to the main element, e.g., Z=14 for SiO2.

Periodic dependence of λi200 on atomic number Z

Figure 4623. Periodic dependence of λi200 on atomic number Z. [16]



[1] Daniels, J., Festenberg, C. V., Raether, H., and Zeppenfeld, K. (1970) Optical constants of solids by electron spectroscopy. In Springer Tracts in Modern Physics, ed. G. Hoehler, Springer, New York, NY, Vol. 54, pp. 78–135.
[2] Colliex, C., Cosslett, V. E., Leapman, R. D., and Trebbia, P. (1976) Contribution of electron energy-loss spectroscopy to the development of analytical electron microscopy. Ultramicroscopy 1, 301–315.
[3] Raether, H. (1980) Excitation of Plasmons and Interband Transitions by Electrons. Springer Tracts in Modern Physics, Springer, New York, NY, Vol. 88.
[4] Colliex, C. (1984) Electron energy-loss spectroscopy in the electron microscope. In Advances in Optical and Electron Microscopy, eds. V. E. Cosslett and R. Barer, Academic, London, Vol. 9, pp. 65–177.
[5] Ahn, C. C., ed. (2004) Transmission Electron Energy Loss Spectrometry in Materials Science and the EELS Atlas, Wiley, New York, NY.
[6] Iakoubovskii, K., Mitsuishi, K., Nakayama, Y., and Furuya, K. (2008) Thickness measurements with electron energy loss spectroscopy. Microsc. Res. Tech. 71, 626–631.
[7] C.J. Powell, J.B. Swan, (1959) Phys. Rev. 115, 869.
[8] E.D. Johnson, R.P. Merrill, (1985) J. Vac. Sci. Technol. A3, 1313.
[9] C.J. Powell, J.B. Swan, (1960) Phys. Rev. 118, 640.
[10] E.D. Johnson, R.P. Merrill, (1985) J. Vac. Sci. Technol. A3, 1313.
[11] G. Gergely, M. Menyhard, A. Sulyok, (1986) Vacuum 36, 471.
[12] S.D. Berger, I.G. Salisbury, R.H. Milne, D. Imeson, C.J. Humphreys, (1978) Philos. Mag. B55, 341.
[13] Helena A.E. Hagelin, Jason F. Weaver, Gar B. Hoflund, Ghaleb N. Salaita, Electron energy loss spectroscopic investigation of palladium metal
and palladium(II) oxide, Journal of Electron Spectroscopy and Related Phenomena 124 (2002) 1–14.
[14] Gar B.Hoflund and Gregory R. Corallo, Electron-energy-loss study of the oxidation of polycrystalline tin, Phys. Rev. B 46, 7110–7120 (1992).
[15] R.E. Egerton, Electron Energy-Loss Spectroscopy in the Electron Microscope, Plenum Press, New York, 1996, p. 302.
[16] Konstantin Iakoubovskii, Kazutaka Mitsuishi,Yoshiko Nakayama, and Kazuo Furuya, Mean free path of inelastic electron scattering in elemental solids and oxides using transmission electron microscopy: Atomic number dependent oscillatory behavior, Physical Review B 77, 104102 (2008).

 

 

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

The book author (Yougui Liao) welcomes your comments, suggestions, and corrections, please click here for submission. If you let book author know once you have cited this book, the brief information of your publication will appear on the “Times Cited” page.