A solid-state approach for the low temperature synthesis of Cr3Si hollow particles

In this paper, pure cubic chromium silicide (Cr3Si) hollow particles have been successfully synthesized through the solid-state reaction of chromium sesquioxide, silicon powder and metallic lithium in an autoclave at 600 °C for 10 h. The as-prepared samples were characterized by means of X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy, which showed that the as-prepared samples were cubic phase Cr3Si hollow particles. Furthermore, the oxidation resistance of the obtained Cr3Si sample was also investigated.

Synthetic Strategies for Hollow Particles with Open Holes on Their Surfaces

Hollow particles with open holes on their surfaces, which refer to hollow micro/nano spheres with open structures such as single hole or multi-holes on their surface, have attracted increasing interest...

Formation mechanisms of hollow manganese hexacyanoferrate particles and construction of a multiple-shell structure

The core's preferential dissolution transforms the cubic-core/monoclinic-shell manganese hexacyanoferrate particles into the hollow structure. Applying an additional growth technique, multi-shell hollow particles have also been constructed.

An off-the-shelf microfluidic device for the controllable fabrication of multiple-holed hollow particles and their cell culture application

The microfluidic droplet method has an excellent promise for preparing hollow particles because it can be versatile in realizing multi-level size distribution and scalable in production. However, the application of...

Size Effect on Optical Properties of Silicon Dioxide Hollow Particles

The optical properties of silicon dioxide hollow particles with different size were investigated in UV/visible/near-IR region, as well as X-ray photoelectron spectra were analyzed. Synthesis of SiO2 hollow particles was carried out using a template method. It was established that hollow particle reflectance lower than bulk microparticles. Absorptance in the red and near infrared spectral ranges increases with decreasing size of hollow particles, but in the UV-region conversely. This is due to different absorption centers.

Radiation Induced Defects in Hollow Particles of Zinc Oxide

Radiation stability of ZnO hollow particles under 100 keV proton and electron exposure have been investigated. The experimental data were compared with the calculated ones obtained by modeling in the GEANT4 software package. Hollow particles have better radiation stability compared with bulk microparticles cause by low defects accumulation in the hollow particles, which was confirmed by simulation in GEANT4.

Low Weight Hollow Microspheres of Iron with Thin Dielectric Coating: Synthesis and Microwave Permeability

Spray pyrolysis of an aqueous solution of iron nitrate, proceeded with reduction of the product in hydrogen, gave iron powder with micron-sized hollow particles. Coating these iron particles with SiO2 through tetraethyl orthosilicate hydrolysis prevented interparticle electrical contacts and suppressed DC percolation. This material shows a high ferromagnetic resonance frequency of 18 GHz, low permittivity, and weighs 20% less than common carbonyl iron. Potential microwave applications are for inductors and electromagnetic interference shielding designs.

Direct observation of potential phase at joining interface between p-MgO and n-MgFe2O4

Visualization of the depletion layer is a significant a guideline for the material design of gas sensors. We attempted to measure the potential barrier at the interface of core–shell microspheres composed of p-MgO/n-MgFe2O4/Fe2O3 from the inside out by means of Kelvin probe force microscopy (KPFM) as a first step to visualizing enlargement of the depletion layer. As determined by high-angle annular dark-field scanning transmission electron microscopy, ca. 70% of the microspheres were hollow with a wall thickness of ca. 200 nm. Elemental mapping revealed that the hollow particles were composed of ca. 20 nm of MgO, ca. 80 nm of MgFe2O4, and ca. 100 nm of Fe2O3. A difference of 0.2 V at the p-MgO/n-MgFe2O4 interface was clarified by KPFM measurements of the hollow particles, suggesting that this difference depends on the formation of a p–n junction. The potential barrier enlarged by the formation of a p–n junction was considered to increase the resistance in air (Ra), since the Ra of the core–shell hollow microspheres was higher than that of MgO, Fe2O3, MgO–Fe2O3, and MgO/MgFe2O4/Fe2O3 particles with irregular shapes. Measurement of the potential barrier height by KPFM is a promising potential approach to tuning the gas sensitivity of oxide semiconductors.