BaFe12−xZrxO19 with Zr4+ at 4f1 and 2b sites exhibits an RL of ∼−40 dB and bandwidth of ∼10 GHz at ∼0.8 mm around the millimeter wavelength atmospheric window of 35 GHz.

In this research, SiC f /SiC-B 4 C composites were prepared through slurry impregnation and reaction melting infiltration (RMI). To explore the damage evolution of this composites after oxidation in wet atmosphere, the changes of damage behavior of composites before and after oxidation were studied using acoustic emission (AE) pattern recognition (PR) technology. Results show that since the damage behavior of the composites changes after oxidation, the optimal number of clusters transforms from 3 to 5. In addition, as the oxidation time increases, the area of concentration of damage events is gradually broadened towards lower stress direction due to the decrease of damage threshold of composites. Meanwhile, because the BN interface is gradually oxidized, the density of C3-cracks (axial yarns cracks) near the fracture and the proportion of Cluster-4 (the signals of transverse yarns cracks) will increase, for which the rising of interfacial shear stress should be responsible. Through this research, not only can the damage evolution of SiC f /SiC-B 4 C composites after oxidation be understood, but also the method employed in this research can be as guide for studying other similar materials.

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The piezotronic effect, which utilizes the piezopotential to engineer the interface characteristics, has been widely exploited to design novel functional device or to optimize the device performance, which is intimately related to the carrier concentration. Here, by constructing a general Schottky diode, the piezotronic effect dependence on the carrier concentration was investigated systematically using ultraviolet (UV) illumination. Scanning Kelvin Probe Microscopy was employed to quantify the carrier concentration in ZnO nanorods under UV illumination. The results showed that the carrier concentration increases with increasing light intensity and an average value of up to 5.6 × 10(18) cm(-3) under 1.2 mW cm(-2) light illumination was obtained. Furthermore, with increasing UV light intensity, an increasingly imperceptible variation in the current-voltage characteristics under strain was observed, which finally disappeared under 1.2 mW cm(-2) light illumination. This phenomenon was attributed to the weakened modulation ability of the piezopotential due to the strengthened screening effect. In addition, the gradual disappearing in the barrier also contributed to the gradual disappearance of the piezotronic effect. This study provides an in-depth understanding of piezotronics, which could be extended to other piezoelectric devices and guide the design and optimization of piezotronic and even piezophototronic devices.

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Spin-related emission properties have important applications in the future information technology; however, they involve microscopic ferromagnetic coupling, antiferromagnetic or ferrimagnetic coupling between transition metal ions and excitons, or d state coupling with phonons is not well understood in these diluted magnetic semiconductors (DMS). Fe 3+ doped ZnSe nanoribbons, as a DMS example, have been successfully prepared by a thermal evaporation method. Their power-dependent micro-photoluminescence (PL) spectra and temperature-dependent PL spectra of a single ZnSe:Fe nanoribbon have been obtained and demonstrated that alio-valence ion doping diminishes the exciton magnetic polaron (EMP) effect by introducing exceeded charges. The d-d transition emission peaks of Fe 3+ assigned to the 4 T 2 (G) → 6 A 1 (S) transition at 553 nm and 4 T 1 (G) → 6 A 1 (S) transition at 630 nm in the ZnSe lattice have been observed. The emission lifetimes and their temperature dependences have been obtained, which reflected different spin-phonon interactions. There exists a sharp decrease of PL lifetime at about 60 K, which hints at a magnetic phase transition. These spin-spin and spin-phonon interaction related PL phenomena are applicable in the future spin-related photonic nanodevices.