X-ray photoelectron spectrosopy (XPS), Conversion electron Mössbauerspectroscopy (CEMS) XPS/CEMS

This chamber is located in room MD 441 (extension -2974). It mainly serves for conversion electron Mössbauer spectroscopy (CEMS) and X-ray photoelectron spectroscopy (XPS). Samples may be prepared by molecular beam epitaxy (MBE) and investigated in situ in this chamber.

This UHV system was recently equipped with a high-performance ion getter pump, enabling a base pressure of 10^-10-10^-11mbar. A specially made baffle chamber ensures that no ions can enter the main chamber so that highly sensitive conversion electron Mössbauer spectroscopy measurements can be performed. At present, the chamber contains the following components:

• hemispherical 180° electron analyzer with detector
• electron gun together with a hemispherical analyzer for Auger electron spectroscopy (AES)
• X-ray gun for X-ray photoelectron spectroscopy (XPS) using the hemispherical analyzer
• Conversion electron Mössbauer spectrometer (CEMS) with Be window for in situ investigations in the temperature range of 40 to 400 K using a channeltron as detector
• RHEED optics with CCD camera to record the RHEED diffraction pattern on a fluorescence screen during evaporation
• LEED optics to investigate the surfaces before and after the evaporation process by the diffraction of electrons in the energy range between 20 and 200 eV
• sputter gun for cleaning substrates by Ar⁺ ion bombardment
• up to 6 evaporation cells, computer-controlled, at the users' choice either electron beam evaporators or water-cooled resistively heated Al₂O₃ crucibles
• load lock
• manipulator for moving in three spacial directions and rotation about the polar and azimuthal axes
• sample heating up to 1000 K
• l-He continuous flow cryostat down to 30 K for CEMS measurements