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Room-temperature dilute ferromagnetism has been reported for many semiconducting or insulating materials, which are usually in the forms of bulk or thin film. Here, we successfully fabricated dilute ferromagnetic nanowires by using dislocations---one-dimensional lattice defects---embedded between optically transparent, nonmagnetic $\mathrm{SrTi}{\mathrm{O}}_{3}$ single crystals. At the dislocation cores, we have both locally codoped magnetic $\mathrm{M}{\mathrm{n}}^{2+}$ ions and electron donors. The structure, chemistry, and ferromagnetism of dislocations were studied by atomic-resolution scanning transmission electron microscopy combined with magnetic force microscopy. We discuss the origin of dilute ferromagnetism at the dislocations in terms of the percolation of bound magnetic polarons along the dislocation cores, where antiferromagnetic coupling between the high spin state of $\mathrm{M}{\mathrm{n}}^{2+}$ ions and electron donors leads to the long-range Mn-Mn ferromagnetic exchange interaction.

Inelastic scattering of electrons on crystals can excite lattice vibrations known as phonons. An energy resolution of 10 meV in the scattered electron energy loss has recently been demonstrated in scanning transmission electron microscopy (STEM), permitting experimenters to distinguish between elastic and inelastic scattering events. In this paper the authors present simulations showing that, with the recent improvement in energy resolution, atomic resolution phonon spectroscopy and imaging of crystals using STEM should now be feasible.

Elemental mapping using energy-dispersive x-ray spectroscopy in scanning transmission electron microscopy, a well-established technique for precision elemental concentration analysis at submicron resolution, was first demonstrated at atomic resolution in 2010. However, to date atomic resolution elemental maps have only been interpreted qualitatively because the elastic and thermal scattering of the electron probe confounds quantitative analysis. Accounting for this scattering, we present absolute scale quantitative comparisons between experiment and quantum mechanical calculations for both energy dispersive x-ray and electron energy-loss spectroscopy using off-axis reference measurements. The relative merits of removing the scattering effects from the experimental data against comparison with direct simulations are explored.

The near-edge fine structure of an ionization edge in electron energy-loss spectroscopy provides bonding and elemental information. We investigate the fine structure of the O $K$ edge in SrTiO${}_{3}$, where the oxygen atoms have identical local bonding environments in three dimensions but differ in their two-dimensional projection. By removing the effects of elastic and thermal diffuse scattering in experimental data, we demonstrate a small difference between the O columns that are nonequivalent in projection, which was not evident before the removal of scattering of the probing electrons. We explore the robustness of this method to the uncertainty in various experimental parameters.

Newly developed achromatic electron optics allows the use of wide energy windows and makes feasible energy-filtered transmission electron microscopy (EFTEM) at atomic resolution. In this Letter we present EFTEM images formed using electrons that have undergone a silicon L(2,3) core-shell energy loss, exhibiting a resolution in EFTEM of 1.35 Å. This permits elemental mapping beyond the nanoscale provided that quantum mechanical calculations from first principles are done in tandem with the experiment to understand the physical information encoded in the images.