Electromagnetic Radiation
tranversal waves, velocity c0≈ 3 · 108 m s-1
Range of frequencies for structural analysis: 106-1020Hz i.e. 10-12 – 102 m γ-ray, x-ray, ultraviolet (UV), visible (VIS), infrared (IR), micro-, radiowaves
-frequency -wavelength -wavenumber
ν λ
~ ν ( ν ~
=1
/λ
=ν
/c
0; cm
-1, Kaiser)
(ν = c0/ λ ; s-1, Hz)
(λ = c0/ ν ; Å, nm, ..., m, ...)
4. Phase
phase ϕenergy ~ frequency
~ wavenumber
~ wavelength-1
(E = h · ν) (E = h · c0 / λ)
)
~ c h
(E= ⋅ν ⋅ o
Characteristics
1. Energy (eV, kJ mol
-1)
2. Intensity
cross-section3. Direction
wavevector sr0 I ~|S| E H |2 r r
r =| ×