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Two-dimensional (2D) arsenic–phosphorus (AsP), as a derivative of black phosphorus (BP), has achieved great progress in regards to preparation methods, property modulation, and front application, which can be attributed to the following two points. The first is that a method has been developed of alloying BP with the congener element arsenic to produce high-quality AsP; the second is that stable AsP possesses unique electronic and optical properties. To conclude the continuous and extensive research, this review focuses on synthesis details, modulation strategies, and application advances of stable AsP. Firstly, several pathways to prepare AsP with different phases are listed. Secondly, multiple solutions to optimize the electronic properties of AsP are discussed, such as strain regulation and composition tuning, and especially composition tuning of AsP including element modification, atomic substitution, and dopant participation, which can bring about adjustments of the lattice structure, bandgaps, and electronic properties. Based on the regulated AsP, applications in infrared photodetectors, high-performance transistors, and efficient-energy storage devices and so on have been widely developed. Although there are challenges ahead, this review may bring new insights into and inspirations for further development of 2D AsP-based materials and devices.

In previous experiments, compounds TiC, TaC, and ZrC are often added in W to improve the mechanical and thermal properties. However, it is still not clear how atomic Ti, Ta and Zr coexisted with C will affect H behaviors in W. In this work, systematical \emph{ab initio} calculations are carried out to study the interactions among alloying atoms (Ti, Ta and Zr), H, and C. The results illustrate that substitutional alloying atoms Ti, Ta, and Zr can trap H atom, and increase the retention of H in W. The effect of Ti on raising H retention is the strongest, followed by that of Zr and Ta. All Ti-C, Ta-C, and Zr-C can exist in W, and Zr-C is the most stable while the stability of Ta-C is relatively low. The stability of Ti-C is between Zr-C and Ta-C. The binding strength of Zr-C-H is the largest, followed by that of Ti-C-H and Ta-C-H in W, suggesting H retention in W-Zr-C may be the largest while H retention in W-Ta-C may be relatively low. The movement of H is much easier than that of C in W. The presence of alloying atoms Ti, Ta, and Zr in W affects the movement of H and C: the diffusion of H away from the alloying atoms is more difficult than that moving close to the alloying atoms, while the movement of C atoms approaching the alloying atoms is relatively difficult.

Neutron irradiation induces a large number of vacancies and self-interstitial atoms (SIAs) that interact with hydrogen atoms (H) and degrade the mechanical properties of tungsten (W) in a fusion environment. Vacancies increase free space and trap H atoms, however, the effects of SIAs on trapping H atoms are still unclear since SIAs decrease free space. We therefore perform systematical \emph{ab initio} calculations to study the interactions of SIAs and SIAs clusters with H atoms in W. Our results suggest that SIA $\langle111\rangle$ dumbbell makes interstitial H atoms easy to accumulate in W. With accumulation of H atoms near a SIA $\langle111\rangle$ dumbbell, the binding energy decreases firstly and then levels off at about 0.3 eV. For comparison, the interactions of SIAs and SIAs clusters with helium (He) atoms are considered. It is found that SIAs and SIAs clusters can also act as trapping centers for interstitial He atoms. The combinations of SIAs with H and He hinder the fast movement of SIAs in W to annihilate with vacancies, increasing the concentrations of SIAs and vacancies in grain. SIAs and vacancies provide more sites for trapping H and He atoms and thus increase irradiation damage in W. We therefore suggest reducing retention of H isotopes and He in W to suppress irradiation damage.

W-(0.2, 0.5, 1.0)wt% ZrC alloys with a relative density above 97.5% were fabricated through the spark plasma sintering (SPS) method. The grain size of W-1.0wt% ZrC is about 2.7 μm, smaller than that of pure W and W-(0.2, 0.5)wt% ZrC. The results indicated that the W-ZrC alloys exhibit higher hardness at room temperature, higher tensile strength at high temperature, and a lower ductile to brittle transition temperature (DBTT) than pure W. The tensile strength and total elongation of W-0.5wt% ZrC alloy at 700 °C is 535 MPa and 24.8%, which are respectively 59% and 114% higher than those of pure W (337 MPa, 11.6%). The DBTT of W-(0.2, 0.5, 1.0)wt% ZrC materials is in the range of 500°C–600°C, which is about 100 °C lower than that of pure W. Based on microstructure analysis, the improved mechanical properties of the W-ZrC alloys were suggested to originate from the enhanced grain boundary cohesion by ZrC capturing the impurity oxygen in tungsten and nano-size ZrC dispersion strengthening.

Hardening and elemental segregation of T91 martenstic steel irradiated by 10 MeV Cl ions to doses from 0.06 dpa to 0.83 dpa were investigated with the nanoindentation technique and transmission electron microscopy (TEM). The results demonstrated that the irradiation hardening was closely related with irradiation dose. By increasing the dose, the hardness increased rapidly at first from the initial value of 3.15 GPa before irradiation, and then tended to saturate at a value of 3.58 GPa at the highest dose of 0.83 dpa. Combined with TEM observation, the mechanism of hardening was preliminary attributed to the formation of M(Fe,Cr)23C6 carbides induced by the high energy Cl-ion irradiation.

Effects of Si3+ and H+ irradiation on tungsten were investigated by internal friction (IF) technique. Scanning electron microscope (SEM) analysis revealed that sequential dual Si+H irradiation resulted in more serious damage than single Si irradiation. After irradiation, the IF background was significantly enhanced. Besides, two obvious IF peaks were initially found in temperature range of 70~330 K in the sequential Si+H irradiated tungsten sample. The mechanism of increased IF background for the irradiated samples was suggested to originate from the high density dislocations induced by ion irradiation. On the other hand, the relaxation peak PL and non-relaxation peak PH in the Si+H irradiated sample were ascribed to the interaction process of hydrogen atoms with mobile dislocations and transient processes of hydrogen redistribution, respectively. The obtained experimental results verified the high sensitivity of IF method on the irradiation damage behaviors in nuclear materials.

He-charged oxide dispersion strengthened (ODS) FeCrNi films were prepared by a radio-frequency (RF) plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C. As a comparison, He-charged FeCrNi films were also fabricated at the same conditions through direct current (DC) plasma magnetron sputtering. The doping of He atoms and Y2O3 in the FeCrNi films was realized by the high backscattered rate of He ions and Y2O3/FeCrNi composite target sputtering method, respectively. Inductive coupled plasma (ICP) and x-ray photoelectron spectroscopy (XPS) analysis confirmed the existence of Y2O3 in FeCrNi films, and Y2O3 content hardly changed with sputtering He/Ar ratio. Cross-sectional scanning electron microscopy (SEM) shows that the FeCrNi films were composed of dense columnar nanocrystallines and the thickness of the films was obviously dependent on He/Ar ratio. Nanoindentation measurements revealed that the FeCrNi films fabricated through DC/RF plasma magnetron sputtering methods exhibited similar hardness values at each He/Ar ratio, while the dispersion of Y2O3 apparently increased the hardness of the films. Elastic recoil detection (ERD) showed that DC/RF magnetron sputtered FeCrNi films contained similar He amounts (~17 at.%). Compared with the minimal change of He level with depth in DC-sputtered films, the He amount decreases gradually in depth in the RF-sputtered films. The Y2O3-doped FeCrNi films were shown to exhibit much smaller amounts of He owing to the lower backscattering possibility of Y2O3 and the inhibition effect of nano-sized Y2O3 particles on the He element.

A reflection-type space-division optical switch is theoretically proposed and experimentally demonstrated based on the electrically tuned Goos?H?nchen effect in a symmetrical metal-cladding waveguide which employs the PMN?PT ceramics as the guiding layer. Owing to the high sensitivity of the ultrahigh-order modes, the variation of refractive index and thickness induced by the exertion of the controlled voltage on the PMN?PT ceramics will easily give rise to a change in the position of the reflected light. In the experiment, a three-pinhole array is put in the reflected light path and a one-to-three optical switch is achieved. The switching time for 10%?90% light intensity change and the optical crosstalk are measured to be lower than 1.63??s and ?29?dB, respectively. Since the Goos?H?nchen shift can reach approximately 1?mm, the number of output ports can be further increased on condition that the utilized incident light has a smaller spot diameter.

We report results of experiments and calculations that help to clarify the underlying physics of the light matter interaction in a symmetrical metal cladding ferrofluids core waveguide chip. Without applying external magnetic field, the observed tunable reflectivity confirms the formation of regular particle aggregates in the ferrofluids under the excited ultrahigh-order modes. A tentative explanation is proposed based on the competition between the optical trapping effect and the Soret effect as the field intensity increases.