Scattering of electron vortex beams on a magnetic crystal: towards atomic resolution magnetic measurements

Abstract

Use of electron vortex beams (EVB), that is convergent electron beams carrying an orbital angular momentum (OAM), is a novel development in the field of transmission electron microscopy. They should allow measurement of element-specific magnetic properties of thin crystals using electron magnetic circular dichroism (EMCD)---a phenomenon similar to the x-ray magnetic circular dichroism. Recently it has been shown computationally that EVBs can detect magnetic signal in a scanning mode only at atomic resolution. In this follow-up work we explore in detail the elastic and inelastic scattering properties of EVBs on crystals, as a function of beam diameter, initial OAM, acceleration voltage and beam displacement from an atomic column. We suggest that for a 10 nm layer of bcc iron oriented along (001) zone axis an optimal configuration for a detection of EMCD is an EVB with OAM of $1\hslash$ and a diameter of 1.6 Å, acceleration voltage 200 keV and an annular detector with inner and outer diameters of $G$ and $5G$, respectively, where $\mathbf{G}=(100)$.

13 pages, 12 figures, submitted. arXiv admin note: text overlap with arXiv:1304.5461

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Cited by in corpus (12)

• Electromagnetic Angular Momentum
• Electromagnetic Force and Momentum
• Holographic generation of highly twisted electron beams
• Achieving atomic resolution magnetic dichroism by controlling the phase symmetry of an electron probe
• Scattering of twisted electron wave-packets by atoms in the Born approximation
• Magnetic Effects in the Paraxial Regime of Elastic Electron Scattering
• Prospects for versatile phase manipulation in the TEM: beyond aberration correction
• Electric quadrupole moment and the tensor magnetic polarizability of twisted electrons and a potential for their measurements
• USID and Pycroscopy -- Open frameworks for storing and analyzing spectroscopic and imaging data
• Siberian snake-like behavior for an orbital polarization of a beam of twisted (vortex) electrons
• Sub-10 nm Quantification of Spin and Orbital Magnetic Moment Across the Metamagnetic Phase Transition in FeRh Using EMCD
• Paraxial Dirac equation