Quantitative spin polarization analysis in photoelectron emission microscopy with an imaging spin filter

Using a photoelectron emission microscope (PEEM), we demonstrate spin-resolved electron spectroscopic imaging of ultrathin magnetic Co films grown on Cu(100). The spin-filter, based on the spin-dependent reflection of low energy electrons from a W(100) crystal, is attached to an aberration corrected electrostatic energy analyzer coupled to an electrostatic PEEM column. We present a method for the quantitative measurement of the electron spin polarization at 4×103 points of the PEEM image, simultaneously. This approach uses the subsequent acquisition of two images with different scattering energies of the electrons at the W(100) target to directly derive the spin polarization without the need of magnetization reversal of the sample.

► Spin-resolved electron spectroscopic imaging of ultrathin magnetic Co films. ► Electron reflection at a W(100) single crystal is used as imaging spin filter. ► Four orders of magnitude increased efficiency over conventional spin detectors. ► Imaging of magnetic domains on a ferromagnetic film by intensity contrast. ► Quantitative measurement of spin polarization in photoelectron emission microscopy.