x-ray photoemission electron microscopy

**XPEEM** (X-Ray Photoemission Electron Microscopy) is a **full-field imaging technique that uses X-ray excited photoelectrons to create spatially resolved chemical maps** — combining the chemical sensitivity of XPS with ~20-50 nm spatial resolution for surface imaging. **How Does XPEEM Work?** - **Excitation**: Tunable synchrotron X-rays illuminate the sample (full field, no scanning). - **Photoelectrons**: X-ray excited photoelectrons are emitted from the surface. - **Electron Optics**: An electrostatic or magnetic lens system images the photoelectron distribution onto a 2D detector. - **Spectroscopy**: By tuning the X-ray energy or electron energy filter, collect chemical-state maps. **Why It Matters** - **Chemical Imaging**: Maps elemental composition AND chemical state with 20-50 nm resolution. - **Magnetic Imaging**: With circularly polarized X-rays (XMCD), images magnetic domain structures. - **Surface Sensitivity**: ~1-3 nm probing depth (like XPS) but with spatial resolution. **XPEEM** is **XPS with a magnifying glass** — creating nanoscale chemical-state images using photoemitted electrons.