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The antiperovskite ferrimagnet Mn4N has perpendicular magnetic anisotropy and small spontaneous magnetization, both of which are favorable properties for current induced domain wall motion. Previously we have investigated the magnetic structure of 3d-element-doped Mn4N thin films and demonstrated ultrafast domain wall velocities reaching 3000 m s−1 in the vicinity of the magnetic compensation composition of Ni-doped Mn4N at the current density of j = 1.2 × 1012 A m−2 at room temperature (RT). In this study, we investigate the effect of Au doping on the magnetic structure of Mn4N films, and present a composition ratio-dependent sign reversal of the anomalous Hall effect at RT. X-ray magnetic circular dichroism measurement revealed that the magnetic moment of the face-centered Mn atoms of Mn4−xAuxN reversed between x = 0.1 and 0.2, and became parallel to that of the corner-site Mn atoms for x = 0.2 and 0.3. This result suggests that the ferrimagnetic-ferromagnetic phase transition occurred in Au-doped Mn4N epitaxial films as in the In-doped Mn4N epitaxial films. [ABSTRACT FROM AUTHOR]

Context: Periodic assessment of knee extensor muscle strength and size is important for all ages to evaluate the functional status of individuals and to identify and treat those at risk for mobility problems and frailty; however, it is not fully understood whether these field-based simplified approaches correspond to evaluation in knee extensor muscle strength or size. Objective: To examine the relationship between field-based simplified evaluation approaches and knee extensor muscle strength or size in young women. Design: Experimental. Setting: University research laboratory. Subjects: A total of 62 university freshmen women volunteered to participate in this study. Main Outcome Measures: Knee extensor muscle thickness was measured at the anterior half of thigh length; muscle strength was measured when subjects performed knee extension. Field-based simplified approaches (sit-to-stand, standing long jump, handgrip, and upper leg 50% [thigh] girth) were also measured. Results: Maximal strength was correlated with thigh girth, handgrip, and standing long jump, but not with the sit-to-stand test. Muscle thickness was correlated with thigh girth and handgrip, but not with standing long jump or the sit-to-stand test. A stepwise multiple-regression analysis was calculated using the predictor thigh girth and standing long jump to predict knee extensor maximal strength (R2 =.295). To predict knee extensor muscle thickness, the predictor thigh girth was calculated (R2 =.202). Conclusions: Knee extensor muscle strength and size could be evaluated by the field-based simplified approaches, in particular by the thigh girth measurement, which may be a major determinant to maintain activities of daily living for healthy young women. However, the 4 field-based simplified approaches appear to be still not of high impact. [ABSTRACT FROM AUTHOR]

Rare-earth-free Mn4N has attracted increasing attention as a spintronic material thanks to its ferrimagnetism, perpendicular magnetic anisotropy, and controllability of magnetic properties by partial replacement of Mn atoms with other elements. Here, we grew ∼25-nm-thick Mn4−xSnxN epitaxial films (x = 0–1.4) on MgO(001) substrates by molecular beam epitaxy and investigated their lattice constants and magneto-transport properties. The ratio of the out-of-plane lattice constant c to the in-plane lattice constant a in the Mn4−xSnxN films, c/a, was less than 1 for x < 0.9, but it changed to more than 1 for x = 1.0. Amazingly, the sign of the anomalous Hall effect changed twice with increasing x. These results suggest that the magnetic structure of the Mn4−xSnxN films varies with Sn composition. Possible mechanisms of the magnetic structure change include magnetic compensation, ferrimagnetic–ferromagnetic phase transition, and the formation of noncollinear magnetic structures. [ABSTRACT FROM AUTHOR]