Inorganic process for wet silica-doping of calcium phosphate.

Silica is not only a biocompatible trace element but also an essential element for bone formation and metabolism. Therefore, it is often doped into bioceramics such as calcium phosphate and calcium carbonate for enhancing biomaterial ability. Heretofore, organic silica materials are employed as silica sources, but the residual organic matter is a significant drawback in biomaterial applications.

Geometrically stabilized skyrmionic vortex in FeGe tetrahedral nanoparticles.

The concept of topology has dramatically expanded the research landscape of magnetism, leading to the discovery of numerous magnetic textures with intriguing topological properties. A magnetic skyrmion is an emergent topological magnetic texture with a string-like structure in three dimensions and a disk-like structure in one and two dimensions. Skyrmions in zero dimensions have remained elusive due to challenges from many competing orders.

Phase equilibria among -FeAl and its higher-ordered phases.

Phase equilibria among the -FeAl phase and its higher-ordered phases with the framework structure were determined experimentally. The solubility range of the phase at elevated temperature does not differ remarkably from that in previous studies, but this phase is found to undergo complicated phase transformations upon cooling. Four phases are present, namely ', ", "' and , with higher-order atomic orderings in the -axis chain sites of the orthorhombic crystal structure of the parent phase.

Aesthetic Silver-Doped Octacalcium Phosphate Powders Exhibiting Both Contact Antibacterial Ability and Low Cytotoxicity.

Since the introduction of biomaterials, infection has been a serious problem in clinical operations. Although several studies have introduced hybrid materials of calcium phosphate and Ag nanoparticles (NPs) that exhibit antibacterial activity, released Ag ions and Ag NPs are highly cytotoxic and the materials require complex fabrication techniques such as laser irradiation. In this study, we introduce a simple one-pot synthesis method based on crystal-engineering techniques to prepare Ag-substituted octacalcium phosphate (OCP-Ag) powder that simultaneously exhibits antibacterial activity, little change in color, and low cytotoxicity, thereby overcoming the shortcomings of calcium phosphate as a biomaterial.

Electron Holography and Magnetotransport Measurements Reveal Stabilized Magnetic Skyrmions in FeCoSi Nanowires.

Magnetic skyrmions are topological spin textures that have shown promise for future nonvolatile memory devices. Herein, we report on the stability of magnetic skyrmions in alloyed cubic B20 FeCoSi nanowires (NWs) determined using off-axis electron holography and magnetotransport measurements. This study presents the real space observation of one-dimensional skyrmion lattice in a NW of FeCoSi which shows that the skyrmion phase in a FeCoSi NW exists at lower applied magnetic fields (200 Oe) with a reduced domain size (28 ± 2 nm) in comparison to bulk and thin film samples.

Electron holography on Fraunhofer diffraction.

Electron holography in Fraunhofer region was realized by using an asymmetric double slit. A Fraunhofer diffraction wave from a wider slit worked as an objective wave interfered with a plane wave from a narrower slit as a reference wave under the pre-Fraunhofer condition and recorded as a hologram. Here, the pre-Fraunhofer condition means that the following conditions are simultaneously satisfied: single-slit observations are performed under the Fraunhofer condition and the double-slit observations are performed under the Fresnel condition.

Current-Driven Motion of Domain Boundaries between Skyrmion Lattice and Helical Magnetic Structure.

To utilize magnetic skyrmions, nanoscale vortex-like magnetic structures, experimental elucidation of their dynamics against current application in various circumstances such as in confined structure and mixture of different magnetic phases is indispensable. Here, we investigate the current-induced dynamics of the coexistence state of magnetic skyrmions and helical magnetic structure in a thin plate of B20-type helimagnet FeGe in terms of in situ real-space observation using Lorentz transmission electron microscopy. Current pulses with various heights and widths were applied, and the change of the magnetic domain distribution was analyzed using a machine-learning technique.

Interference experiment with asymmetric double slit by using 1.2-MV field emission transmission electron microscope.

Advanced electron microscopy technologies have made it possible to perform precise double-slit interference experiments. We used a 1.2-MV field emission electron microscope providing coherent electron waves and a direct detection camera system enabling single-electron detections at a sub-second exposure time.

Magnetic field observations in CoFeB/Ta layers with 0.67-nm resolution by electron holography.

Nanometre-scale magnetic field distributions in materials such as those at oxide interfaces, in thin layers of spintronics devices, and at boundaries in magnets have become important research targets in materials science and applied physics. Electron holography has advantages in nanometric magnetic field observations, and the realization of aberration correctors has improved its spatial resolution. Here we show the subnanometre magnetic field observations inside a sample at 0.

Secondary electron effect on electron beam induced charging of SiO2 particle analyzed by electron holography.

Charging of a SiO2 particle induced by electron illumination was investigated by changing the illuminated area of the particle and its support film through control of the position of the mask plate inserted in a transmission electron microscope illumination system. The electric fields around the charged SiO2 particle were analyzed using electron holography. The amount of charge was evaluated quantitatively by comparing the reconstructed phase images with the simulated phase images.