The manipulation of spin textures with electric currents is an important challenge in the field of spintronics. many attempts have been made to electrically drive magnetic domain walls in ferromagnets, yet the necessary current density remains quite high (~10 7 A cm − 2 ). A recent neutron study combining Hall effect measurements has shown that an ultralow current density of J~10 2 A cm − 2 can trigger the rotational and translational motion of the skyrmion lattice in mnsi, a helimagnet, within a narrow temperature range. Raising the temperature range in which skyrmions are stable and reducing the current required to drive them are therefore desirable objectives. Here we demonstrate near-room-temperature motion of skyrmions driven by electrical currents in a microdevice composed of the helimagnet FeGe, by using in-situ Lorentz transmission electron microscopy. The rotational and translational motions of skyrmion crystal begin under critical current densities far below 100 A cm − 2 .

Microstructure characterization has become indispensable to the study of complex materials, such as strongly correlated oxides, and can obtain useful information about the origin of their physical properties. Although atomically resolved measurements have long been possible, an important goal in microstructure characterization is to achieve element-selective imaging at atomic resolution. A combination of scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) is a promising technique for atomic-column analysis. However, two-dimensional analysis has not yet been performed owing to several difficulties, such as delocalization in inelastic scattering or instrumentation instabilities. Here we demonstrate atomic-column imaging of a crystal specimen using localized inelastic scattering and a stabilized scanning transmission electron microscope. The atomic columns of La, Mn and O in the layered manganite La1.2Sr1.8Mn2O7 are visualized as two-dimensional images.

New oxides, BiAlO 3 and BiGaO 3 , were prepared using a high-pressure high-temperature technique at 6 GPa and 1273-1473 K. BiAlO 3 is isotypic with multiferroic perovskite-like BiFeO 3 and has octahedrally coordinated Al 3+ ions. Structure parameters of BiAlO 3 were refined from laboratory X-ray powder diffraction data (space group R3c; Z ) 6; a ) 5.37546(5) Å and c ) 13.3933(1) Å). BiGaO 3 has the structure closely related to pyroxene-like KVO 3 . Structure parameters of BiGaO 3 were refined from timeof-flight neutron powder diffraction data (space group Pcca; Z ) 4; a ) 5.4162(2) Å, b ) 5.1335(3) Å, and c ) 9.9369(5) Å). The GaO 4 tetrahedra in BiGaO 3 are joined by corners forming infinite (GaO 3 ) 3chains along the a axis. Bi 3+ ions in BiGaO 3 have 6-fold coordination. Both BiAlO 3 and BiGaO 3 decompose at ambient pressure on heating above 820 K to give Bi 2 M 4 O 9 and Bi 25 MO 39 (M ) Al and Ga). Vibrational properties of BiAlO 3 and BiGaO 3 were studied by Raman spectroscopy. In solid solutions of BiAl 1-x Ga x O 3 , a C-centered monoclinic phase structurally related to PbTiO 3 with lattice parameters of a ) 5.1917(4) Å, b ) 5.1783(4) Å, c ) 4.4937(3) Å, and β ) 91.853(3)°was found.