Novel uniform-sized, core-shell ZnO mesocrystal microspheres have been synthesized on a large scale using a facile one-pot hydrothermal method in the presence of the water-soluble polymer poly(sodium 4-styrenesulfonate). The mesocrystal forms via a nonclassical crystallization process. The intrinsic dipole field introduced by the nanoplatelets as a result of selective adsorption of the polyelectrolyte on some polar surfaces of the nanoparticles acts as the driving force. In addition, it plays an important role throughout the mesoscale assembly process from the creation of the bimesocrystalline core to the apple-like structure and finally the microsphere. Our calculation based on a dipole model confirms the dipole-field-driven mechanism forming the apple-like structure.

Bi2Se3 attracts intensive attention as a typical thermoelectric material and a promising topological insulator material. However, previously reported Bi2Se3 nanostructures are limited to nanoribbons and smooth nanoplates. Herein, we report the synthesis of spiral Bi2Se3 nanoplates and their screw-dislocation-driven (SDD) bidirectional growth process. Typical products showed a bipyramid-like shape with two sets of centrosymmetric helical fringes on the top and bottom faces. Other evidence for the unique structure and growth mode include herringbone contours, spiral arms, and hollow cores. Through the manipulation of kinetic factors, including the precursor concentration, the pH value, and the amount of reductant, we were able to tune the supersaturation in the regime of SDD to layer-by-layer growth. Nanoplates with preliminary dislocations were discovered in samples with an appropriate supersaturation value and employed for investigation of the SDD growth process.

Here, we report the realization of epitaxial Y3Fe5O12 (YIG) thin films with perpendicular magnetic anisotropy (PMA). The films are grown on the substituted gadolinium gallium garnet substrate (SGGG) by pulsed laser deposition. It was found that a thin buffer layer of Sm3Ga5O12 (SmGG) grown on top of SGGG can suppress the strain relaxation, which helps induce a large enough PMA to overcome the shape anisotropy in YIG thin films. The reciprocal space mappings analysis reveals that the in-plane strain relaxation is suppressed, while the out-of-plane strain relaxation exhibits a strong dependence on the film thickness. We found that the PMA can be achieved for both bilayer (YIG/SmGG) and tri-layer (SmGG/YIG/SmGG) structural films with YIG layer thicknesses up to 20 nm and 40 nm, respectively.

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The photocurrent of a CuIn0.7Ga0.3S2 nano-photocathode increases about 2–3 times after selective etching of a metastable CuAu ordering phase.

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