Room-temperature ferromagnetism of 2H-SiC-α-Al2O3 solid solution nanowires and the physical origin

Effect of Fe-doping on bending elastic properties of single-crystalline rutile TiO2 nanowires

Transition-metal-doping can improve some physical properties of titanium dioxide (TiO₂) nanowires (NWs), which leads to important applications in miniature devices. Here, we investigated the elastic moduli of single-crystalline pristine and Fe-doped rutile TiO₂ NWs using the three-point bending method, which is taken as a case study of impacts on the elastic properties of TiO₂ NWs caused by transition-metal-doping. The Young's modulus of the pristine rutile TiO₂ NWs decreases when the cross-sectional area increases (changing from 246 GPa to 93.2 GPa). However, the elastic modulus of the Fe-doped rutile NWs was found to increase with the cross-sectional area (changing from 91.8 GPa to 200 GPa). For NWs with similar geometrical size, the elastic modulus (156.8 GPa) for Fe-doped rutile NWs is 24% smaller than that (194.5 GPa) of the pristine rutile TiO₂ NWs. The vacancies generated by Fe-doping are supposed to cause the reduction of elastic modulus of rutile TiO₂ NWs. This work provides a fundamental understanding of the effects of transition-metal-doping on the elastic properties of TiO₂ NWs.

Selective growth of zinc blende, wurtzite and hybrid SiC nanowires via a simple chemical vapor deposition route

3C-SiC, 2H-SiC and their hybrid nanowires were synthesized in a controllable manner via changing CH₄ flow rates. It is found that higher CH₄ supply facilitates the wurtzite phase growth, while the other phases formed when decreasing the flow rate.

Flexible Transparent and Free-Standing SiC Nanowires Fabric: Stretchable UV Absorber and Fast-Response UV-A Detector

Transparent and flexible materials are desired for the construction of photoelectric multifunctional integrated devices and portable electronics. Herein, 2H-SiC nanowires are assembled into a flexible, transparent, self-standing nanowire fabric (FTS-NWsF). The as-synthesized ultralong nanowires form high-quality crystals with a few stacking faults. The optical transmission spectra reveal that FTS-NWsF absorbs most incident 200-400 nm light, but remains transparent to visible light. A polydimethylsiloxane (PDMS)-SiC fabric-PDMS sandwich film device exhibits stable electrical output even when repeatedly stretched by up to 50%. Unlike previous SiC nanowires in which stacking faults are prevalent, the transparent, stretchable SiC fabric shows considerable photoelectric activity and exhibits a rapid photoresponse (rise and decay time < 30 ms) to 340-400 nm light, covering most of the UV-A spectral region. These advances represent significant progress in the design of functional optoelectronic SiC nanowires and transparent and stretchable optoelectronic systems.

Extremely Stable Current Emission of P-Doped SiC Flexible Field Emitters

Novel P-doped SiC flexible field emitters are developed on carbon fabric substrates, having both low E_to of 1.03-0.73 Vμm^-1 up to high temperatures of 673 K, and extremely high current emission stability when subjected to different bending states, bending circle times as well as high temperatures (current emission fluctuations are typically in the range ±2.1%-3.4%).

Electronic and magnetism properties of two-dimensional stacked nickel hydroxides and nitrides

Two-dimensional (2D) layered materials receive a lot of attention because of their outstanding intrinsic properties and wide applications. In this work, the structural, electronic and magnetic properties of nickel hydroxides (Ni(OH)2) and nitrides XN (X = B, Al, and Ga) heterostructures are studied by first-principles calculations. The results show that the pristine monolayer Ni(OH)2 owns no macro magnetism with antiferromagnetic (AFM) coupling between two nearest Ni atoms, the electronic structure can be modulated through the heterostructures. The Ni(OH)2-GaN and Ni(OH)2-AlN heterostructures retain the AFM coupling, while Ni(OH)2-BN heterostructure have a larger magnetic moment with ferromagnetic (FM) coupling. The complete electron-hole separation is found in the Ni(OH)2-GaN heterostructure. The tunable electronic and magnetic properties of the Ni(OH)2-XN heterostructures open a new door to design the spintronic devices in the 2D stacked nanostructures.