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In this study, nanosized ZnO and Zn1−xFexO powders were synthesized using the flame aerosol synthesis (FAS) method. The microstructure of the ZnO powder shows a significant difference with different precursor concentrations. By adding Fe to the precursor, nanosized Zn1−xFexO powder (x = 0~0.1) can be easily fabricated. The phase formation, microstructure, and infrared absorption properties were systematically investigated by XRD, SEM, TEM, and IR. With the substitution of Fe into the Zn site, lattice distortion occurred, resulting in excellent infrared absorption properties. Compared to other conventional synthesis methods, the FAS method has the advantages of high yield, high crystallinity, and low cost; furthermore, nanosized powder is easily obtained. The FAS method is believed to be one of the best choices for the large-scale production of ZnO and Zn1−xFexO powders.

In this work, the effect of cold rolling and heat treatment upon the microstructure and texture of the surface layer and cross-section of Ni5W alloy substrate was analyzed via the EBSD technique. A typical copper deformation texture was shown by the cold-rolled Ni5W alloy substrate. The cube-oriented nuclei were attributed to the rolling direction&ndash, transverse direction (RD-TD) plane due to the presence of copper and S rolling textures. Typical large-shape cold-rolled microstructure was presented by the RD-ND surface in the cube-oriented area. During the recrystallization process, the cube-oriented grains did not have a nucleation quantity advantage, but they did have an obvious growth advantage compared with other orientation grains. They can form a strong cube texture by absorbing the random orientation and rolling orientation through the migration of large-angle grain boundaries.

In this study, boron powder with different particle sizes was purified by both chemical and heat treatment methods. The reduction in the particle size can improve the chemical purification with no effort on the heat treatment. The superconducting properties of the powder drastically changed even with only a partial elimination of oxygen. On the one hand, less oxygen content resulted in high Tc and Jc values under the low magnetic field, and most importantly, a significant improvement in the superconducting connectivity (Af value). On the other hand, the degradation of Jc under a high field and a change in the pinning mechanism were also found, along with decreasing oxygen. This result indicated that oxygen, probably MgO, might act as the pinning center and as an obstacle for the supercurrent in MgB2 at the same time. This work paves the way for obtaining pure oxygen-free MgB2 and understanding the real effect of oxygen in MgB2.

ErBa2Cu3O7&minus, &delta, (Er123) superconductor is one of the best candidates of superconductor solder for the fabrication of superconducting joint between GdBa2Cu3O7&minus, (Gd123) coated conductor, due to its high Tc value (93 K) and highest optimized oxygen annealing temperature among RE123 compounds. In this paper, we systematically research the effect of sintering parameters on the phase formation, microstructure and superconducting properties of Er123 powder. The optimized synthesis route to acquire high purity Er123 powder with as good superconducting properties as Gd123 has been uncovered. The melt temperature of Er123 with different dopant compared to Gd123 is also investigated, and the feasible operating temperature range of Er123 superconductor solder is discussed. This work reveals a very important starting point on fabrication high-quality superconducting joint between the commercial Gd123 coated conductor, which can further improve the development of the persistent operating mode on ultra-high field nuclear magnetic resonance and magnetic resonance imaging.

The growth of AlGaN has been extensively studied, but corresponding research related to the effect of AlN substrate surface has rarely been reported in literature. In this article, the effects of AlN substrate surface on deposition of AlGaN films were investigated by molecular dynamics (MD) simulations. (0001) Al-terminated and (0001&macr, ) N-terminated AlN were considered as substrates. The quality of surface morphology and atomic scale structure of deposited AlGaN film are discussed in detail. The results show that the surface morphology and crystal quality of AlGaN film grown on (0001) Al-terminated AlN surface are better than for that grown on (0001&macr, ) N-terminated AlN surface under various growing temperatures and Al/Ga injection ratios between Al and Ga. This can be attributed to the higher mobility of Al and Ga adatoms on the (0001) Al-terminated AlN surface. These findings can provide guidance for the preparation of high-quality AlGaN thin films on AlN substrate.