CEMS - Conversion Electron Mössbauer Spectroscopy

The scheme of ⁵⁷Fe nucleus deexcitation after recoil-free absorption of 14.4 keV γ-quantum. For surface studies the most efficient is detection of conversion electrons (and Auger electrons as well).

conversion electrons

e^-: 14.3 keV (1%)

e^-: 13.6 keV (9%)

e^-: 7.3 keV (81%)

γ: 14.4 keV (9%)

ADVANTAGES of the METHOD

• full sample characterization on global atomic scale

• sensitivity below 1 atomic layer for ⁵⁷Fe (so far as the soure is strong)

• buried layer visible

• local

• element specific (probe layer analysis)

• UHV compatible

⁵⁶Fe

⁵⁷Fe

⁵⁶Fe

EXAMPLES of CEMS SPECTRA: Fe(001)/MgO(001)

2ML ⁵⁷Fe

thick ⁵⁶Fe

2ML ⁵⁶Fe

2ML ⁵⁷Fe

thick ⁵⁶Fe