Search

The characteristic of self-recovery holds significant implications for upholding performance stability within flexible electronic devices following the release of mechanical deformation. Herein, the dynamics of self-recovery in a buckling inorganic membrane is studied via in situ scanning probe microscopy technology. The experimental results demonstrate that the ultimate deformation ratio of the buckling BaTiO3ferroelectric membrane is up to 88%, which is much higher than that of the buckling SrTiO3dielectric membrane (49%). Combined with piezoresponse force microscopy and phase-field simulations, we find that ferroelectric domain transformation accompanies the whole process of buckling and self-recovery of the ferroelectric membrane, i.e., the presence of the nano-cdomain not only releases part of the elastic energy of the membrane but also reduces the interface mismatch of the a/cdomain, which encourages the buckling ferroelectric membrane to have excellent self-recovery properties. It is conceivable that the evolution of ferroelectric domains will play a greater role in the regulation of the mechanical properties of ferroelectric membranes and flexible devices.

Binary metal oxide memristor-based artificial neural synapses offer the advantages of high-density information storage, high-efficiency computing, low power consumption, and strong antiradiation damage and are therefore promising aerospace electronic devices. However, the unclear damage trends and mechanisms causing nonlinearity and asymmetry during conductance tuning under irradiation have restricted further development. Here, the damage trends and mechanisms caused by proton irradiation in Au/HfOx/TiOx/Ti memristors were studied. Results show that when the fluence of the proton (25 MeV) irradiation increases to $2\times 10^{11}$ p/cm2, the Au/HfOx/TiOx/Ti memristor cannot return to its original high-resistance state upon conductance reduction, making the conductance tuning less linear and symmetric. X-ray photoelectron spectroscopy (XPS) analysis revealed that the mechanism underlying the decrease in the linearity and symmetry of the conductance tuning is proton irradiation increasing oxygen vacancies in the heterojunction. These results can guide the better design of metal oxide memristive devices suitable for aerospace devices and better modeling of devices with nonideal properties under irradiation.

The degradation trend and the degradation mechanism of the total ionizing dose effects on the TiO2 nano-rod arrays (NRAs)-based resistive random access memory (ReRAM) is studied by exploiting the memory to the 60Co $\gamma $ -rays. The results show that the typical bipolar ${I}$ – ${V}$ behaviors of the prepared Pt/TiO2 NRAs/Ti ReRAM can be shown clearly after 1 Mrad (Si) irradiation. In detail, the resistance of the high resistance state (HRS) decreases with the total dose, while the low resistance state (LRS) is almost unchanged. When the radiation dose reaches 1 Mrad (Si), the value of HRS resistance is reduced by about 1 order of magnitude. Moreover, the RESET voltage shows a slight decrease with the total dose. X-ray photoelectron spectrometer (XPS) characterization of resistive switching materials shows that the radiation-induced non-lattice oxygen and oxygen vacancy are the main reason for the degradation of the HRS and RESET voltage. Based on the results, a mathematical model of the ${I}$ – ${V}$ curves which can suggest the changes of the resistance and voltage simultaneously for the ReRAM under irradiation is developed based on the VTEAM model. The simulation results under different total dose of irradiation are in good agreement with the experimental results. The results can provide a basis and guidance for the research on irradiation effect and the radiation hardening for the oxide-based ReRAM.

TiAlN/AlCrSiN multilayer coatings were prepared by arc ion plating. The implements of various thickness ratio (0, 0.89, 1.04, 1.14 and 1.49) of TiAlN/AlCrSiN on microstructure, mechanical properties and thermal stability of TiAlN/AlCrSiN multilayer coatings were investigated. The AlCrSiN single coating without TiAlN inserted layer exhibits a mixed-phase structure of c-AlN and c-CrN, while TiAlN/AlCrSiN multilayer coatings show a single-phase cubic structure. As the thickness ratio of TiAlN/AlCrSiN increases, the critical load of multilayer coating gradually increases up to 99 N, the hardness decreases and the thermal stability improved. The TiAlN/AlCrSiN multilayer coating with a high thickness ratio of 1.49 was able to maintain a single (200) preferred c-TiAlN/AlCrN solid solution phase structure after annealing at 800°C in Ar for 2 h. The obtained single-phase cubic structure of AlCrSiN at room temperature and the improved thermal stability properties can be explained by the template effect of TiAlN on the AlCrSiN.

ABSTRACTTiAlN/AlCrSiN multilayer coatings were prepared by arc ion plating. The implements of various thickness ratio (0, 0.89, 1.04, 1.14 and 1.49) of TiAlN/AlCrSiN on microstructure, mechanical properties and thermal stability of TiAlN/AlCrSiN multilayer coatings were investigated. The AlCrSiN single coating without TiAlN inserted layer exhibits a mixed-phase structure of c-AlN and c-CrN, while TiAlN/AlCrSiN multilayer coatings show a single-phase cubic structure. As the thickness ratio of TiAlN/AlCrSiN increases, the critical load of multilayer coating gradually increases up to 99 N, the hardness decreases and the thermal stability improved. The TiAlN/AlCrSiN multilayer coating with a high thickness ratio of 1.49 was able to maintain a single (200) preferred c-TiAlN/AlCrN solid solution phase structure after annealing at 800°C in Ar for 2 h. The obtained single-phase cubic structure of AlCrSiN at room temperature and the improved thermal stability properties can be explained by the template effect of TiAlN on the AlCrSiN.

The flexible memristor synapses based on binary metal oxides have significant potential in building artificial neural networks to meet people's demands. To obtain flexible memristor synapses with high linearity of conductance update, herein, the effect of Al doping and SiOxlayer adding on the flexible TiOx‐based memristor synapse even under bending is studied. The results show that the doping Al and adding SiOxlayer improves the linearity of conductance update by 3 times. The bending test results of the SiOx/Al:TiOx‐based memristor synapse show that the linearity decreases slightly with the decrease of the bending radius. When the bending radius is reduced to 5 mm, the total nonlinearity (NL) value of the device is about 0.42. It is still much smaller than the total NL value of TiOx‐based memristor synapse in flat state (about 0.76). The test results of conducting atomic force microscopy show that the improvement of linearity is due to the optimization of conductive filaments. The results provide a feasible program for improving linearity of TiOx‐based flexible memristor synapse even under bending, which can support for the development of high‐performance binary metal oxide flexible memristor synapse. Doping Al and adding SiOxlayer improves the linearity of conductance update. The total nonlinearity value of the Al:TiOx/SiOx‐based memristor synapse with the bending radius of 5 mm is still far less about 2 times than the one of the single‐layer undoped TiOxmemristor synapses under flat state.

Negative capacitance effects with fast response times hold great potential for reducing the power consumption in high-frequency nanoelectronics. Nevertheless, the negative capacitance effect faces considerable complexity arising from the dynamic interplay among electrostatic, nucleation energies, and domain evolution. This intricate balance poses a formidable challenge to achieving fast negative capacitance. Herein, we have achieved a fast negative capacitance time of ∼16.23 ns in PbZr0.2Ti0.8O3(PZT) thin film, and our investigation confirms the presence of acicular ferroelastic domains within the PZT thin film. Under reversal electric fields, these acicular ferroelastic domains undergo a unique flipping process, transitioning through domain expansion and contraction. This distinct domain flipping manner accelerates the nucleation and growth of ferroelectric domains, thereby facilitating the observed fast negative capacitance. The realization of fast negative capacitance holds substantial promise for reducing operational time and power consumption, offering prospects for the design of nanoelectronics with significantly lower power requirements.

Lithium–sulfur batteries are recognized as high energy density systems. However, due to the reproducibility of nonpolar S8, polar polysulfide intermediates and the final Li2S during cycling, developing an effective matrix to reduce sulfur consumption in the cathode and improve the cycle stability is still challenging. Herein, a polar and nonpolar matrix consisting of twined multiwalled carbon nanotube (MWCNT) and high nitrogen‐doped porous carbon is designed, in which the twined MWCNT could provide the nonpolar and physical bind, meanwhile, the N‐enriched porous carbon derived from ionic liquid could provide polar and chemical anchoring. The composite is prepared by carbonizing the 1‐ethyl‐3‐methylimidazolium dicyanamide (Emim‐dca) ionic liquid, which is loaded on the intertwined MWCNT. The ionic‐liquid‐derived composite material shows more microporous and low‐diameter mesoporous structures than intertwined MWCNT, and the nitrogen content reaches 7.42 At%. Assembled in lithium–sulfur batteries, the specific capacity of the battery reaches 1558.6 mAh g−1at the first cycle of 0.1 C. After the 300 times cycling at 1 C, the specific capacity still remains 614.34 mAh g−1and the attenuation is only 0.021% for each cycle. Moreover, the attenuation in the changing rate charge–discharge test is weaker than the pure intertwined MWCNT composite cathode. Herein, a nonpolar and polar matrix is comprised of intertwined multiwalled carbon nanotubes (MWCNTs) and ionic‐liquid‐derived nitrogen‐rich porous carbon. Benefiting from the nonpolar physical binding of microporous and mesoporous structure (diameter < 8 nm) and polar chemical anchoring of N‐doped (7.42 At%) carbon, the cathode exhibits a very stable cycle stability of 0.021% attenuation for each cycle with 300 cycles at 1 C.