Electron scattering

Not to be confused with Electron diffraction.
Types of Scattering
Pictorial description of how an electron beam may interact with a sample with nucleus N, and electron cloud of electron shells K,L,M. Showing transmitted electrons and elastic/inelastically scattered electrons. SE is a Secondary Electron ejected by the beam electron, emitting a characteristic photon (X-Ray) γ. BSE is a Back-Scattered Electron, an electron which is scattered backwards instead of being transmitted through the sample.
Electron (
e−
,
β−
)
ParticleElectron
Mass9.10938291(40)×10−31 kg[1]
5.4857990946(22)×10−4 u[1]
[1822.8884845(14)]−1 u[note 1]
0.510998928(11) MeV/c2[1]
Electric Charge−1 e[note 2]
−1.602176565(35)×10−19 C[1]
−4.80320451(10)×10−10 esu
Magnetic Moment−1.00115965218076(27) μB[1]
Spin1⁄2
Scattering
Forces/EffectsLorentz force, Electrostatic force, Gravitation, Weak interaction
MeasuresCharge, Current
CategoriesElastic collision, Inelastic collision, High energy, Low energy
Interactions
e−
—
e−


e−
—
γ


e−
—
e+


e−
—
p


e−
—
n


e−
— Nuclei
TypesCompton scattering
Møller scattering
Mott scattering
Bhabha scattering
Bremsstrahlung
Deep inelastic scattering
Synchrotron emission
Thomson scattering

Electron scattering occurs when electrons are displaced from their original trajectory. This is due to the electrostatic forces within matter interaction or,[2][3] if an external magnetic field is present, the electron may be deflected by the Lorentz force.[4][5] This scattering typically happens with solids such as metals, semiconductors and insulators;[6] and is a limiting factor in integrated circuits and transistors.[2]

Electron scattering has many applications ranging from the use of swift electron in electron microscopes to very high energies for hadronic systems, that allows the measurement of the distribution of charges for nucleons and nuclear structure.[7][8] The scattering of electrons has allowed us to understand that protons and neutrons are made up of the smaller elementary subatomic particles called quarks.[2]

Electrons may be scattered through a solid in several ways:

  • Not at all: no electron scattering occurs at all and the beam passes straight through.
  • Single scattering: when an electron is scattered just once.
  • Plural scattering: when electron(s) scatter several times.
  • Multiple scattering: when electron(s) scatter many times over.

The likelihood of an electron scattering and the degree of the scattering is a probability function of the specimen thickness and the mean free path.[6]

  1. ^ a b c d e "CODATA Internationally recommended values of the Fundamental Physical Constants". NIST Standard Reference Database 121. National Institute of Standards and Technology. Retrieved 23 November 2013.
  2. ^ a b c "electron scattering". Encyclopædia Britannica. Encyclopædia Britannica, Inc. Retrieved 13 October 2013.
  3. ^ "Electron scattering in solids". Ioffe Institute. Department of Applied Mathematics and Mathematical Physics. Retrieved 13 October 2013.
  4. ^ Howe, James; Fultz, Brent (2008). Transmission electron microscopy and diffractometry of materials (3rd ed.). Berlin: Springer. ISBN 978-3-540-73885-5.
  5. ^ Kohl, L. Reimer, H. (2008). Transmission electron microscopy physics of image formation (5th ed.). New York: Springer. ISBN 978-0-387-34758-5.{{cite book}}: CS1 maint: multiple names: authors list (link)
  6. ^ a b "Electron scattering". MATTER. The University of Liverpool. Archived from the original on 15 October 2013. Retrieved 13 October 2013.
  7. ^ B. Frois; I. Sick, eds. (1991). Modern topics in electron scattering. Singapore: World Scientific. Bibcode:1991mtes.book.....F. ISBN 978-9971509750.
  8. ^ Drechsel, D.; Giannini, M. M. (1989). "Electron scattering off nuclei". Reports on Progress in Physics. 52 (9): 1083. Bibcode:1989RPPh...52.1083D. doi:10.1088/0034-4885/52/9/002. S2CID 250912319.


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