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Functionalized elastomer hydrogels with tough and stretchable mechanics are desired soft materials extensively investigated for various field applications from soft electronics to sensors. Herein, we rationally designed a luminescent elastomer hydrogel by combining the functional carbon nitride (CN) unit cross-linkers with hydrophilic polymer chains into three-dimensional (3D) networks. The aqueous exfoliated and dispersed CN initiated the photopolymerization and gelation of an acrylamide (AM) monomer into a polyacrylamide (PAM)-CN elastomer hydrogel (PAM-CN ESH) under Xe light irradiation, without any conventional initiators and cross-linkers. Moreover, the mechanical attributes of toughness, stretchability and shape recovery for the PAM-CN ESH can be modulated by swelling in ethanol and water to form uniform and dense interlinked channels. Besides, the optical transparent PAM-CN ESH presents enhanced stable blue fluorescence emission around 430 nm, and accurately recognizes and detects Al3+ in an aqueous solution with a limit of detection (LOD) of 0.26 μM.

Cerium-based CeMO3 (M = Co, Ni, Cu) perovskites were efficiently synthesized by electrospinning process. The structures, morphologies, elemental compositions, and valence states of CeMO3 perovskites were manifested in detail using X-ray diffraction analysis, Raman spectroscopic analysis, UV–vis diffuse reflectance spectroscopy, scanning electron microscope, transmission electron microscope, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, respectively. The tolerance factor (t) was accurately calculated to confirm the perovskite structure stability. The electrochemical properties of CeMO3 perovskites were investigated, and the specific capacitances of CeCoO3, CeNiO3, and CeCuO3 perovskites are 128, 189, and 117 F g−1 at the current density of 0.5 A g−1, respectively. This study could provide an efficient and potential applications of the cerium-based perovskites into the supercapacitor electrode materials.

A facile synthesis of perovskite-type CeMnO3 nanofibers as a high performance anode material for lithium-ion batteries was demonstrated. The nanofibers were prepared by the electrospinning technique. The characterization of CeMnO3 nanofibers was carried out by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. SEM images manifested nanofibers with a diameter of 470 nm having a rough surface with a porous structure. TEM images were consistent with the observations from the SEM images. The electrochemical properties of CeMnO3 perovskite in lithium-ion batteries were investigated. The CeMnO3 anode exhibited a discharge capacity of 2159 mA h g−1 with a coulombic efficiency of 93.79%. In addition, a high cycle stability and a capacity of 276 mA h g−1 at the current density of 1000 mA g−1 can be effectively maintained due to the high Li+ conductivity in the CeMnO3 anode. This study could provide an efficient and potential application of perovskite-type CeMnO3 nanofibers in lithium-ion batteries.

The resistive switching characteristics of MnO and CeO2 layers with a large resistance ratio (> 105) were demonstrated. The Ag/MnO/CeO2/Pt devices with heterostructures were fabricated. The bipolar resistive switching behaviors were caused by the formation and disruption of conducting filaments in the switching layers. In CeO2 layer, the formation and rupture of conducting filaments was attributed to the reduction-oxidation reaction of CeO2 and CeO2 − x. The conduction mechanisms of ohmic conduction and Schottky emission had been investigated for resistance switching mechanism.

The fabrication of 5 × 5 crossbar array with a line width of 20 μm was demonstrated. The resistive switching characteristics in the bilayer structure of tantalum oxide and manganese oxide were investigated. The Ag/MnO/Ta2O5/Pt devices showed stable bipolar resistive switching properties with high resistance ratio, low switching voltage, and forming-free behavior. The conduction mechanisms of ohmic conduction and Schottky emission had been investigated for resistance switching mechanism.

A facile synthesis of perovskite-type CeMnO

Perovskite type rare earth manganates RMnO3 (LaMnO3, NdMnO3, SmMnO3, and EuMnO3) nanofibers were fabricated by a simple electrospinning process. LaMnO3 nanofibers showed rhombohedral structure, and NdMnO3, SmMnO3, and EuMnO3 nanofibers exhibited orthorhombic structure. The surface structure, phonon modes, optical property, morphology, and valence states of RMnO3 nanofibers were examined. The electrochemical behaviors of RMnO3 nanofibers as supercapacitor electrode materials were explicitly illustrated. It confirms the feasible applications of RMnO3 nanofibers as supercapacitor electrodes. In addition, the magnetic properties of RMnO3 nanofibers were investigated. At room temperature, RMnO3 nanofibers exhibited paramagnetic behaviors. At low temperature, LaMnO3 and NdMnO3 nanofibers presented magnetic transition to ferromagnetic state, while SmMnO3 and EuMnO3 nanofibers showed magnetic transition to antiferromagnetic state.

The synthesis of a sustainable material through carbon nitride (C3N4) chemically grafted on waste-derived carbon including carbonizing coals (PM), melamine-urea-formaldehyde resins (MUF-C-1100), and luffa cylindrical sponges (SG), respectively, and its application as sulfur cathode in lithium-sulfur (Li-S) batteries were demonstrated. The Li-S cell assembled by the sulfur (S) cathode with component from C3N4 grafted coal-derived carbon (PM-CN) possesses a specific capacity of 1269.8 mA h g−1 at 0.05 C. At 1 C, the initial specific capacity of PM cathode is only 380.0 mA h g−1, comparable to the PM-CN5 cathode of 681.9 mA h g−1, and PM-CN10 cathode of 580.7 mA h g−1, respectively. And, PM-CN 5 cathode presents the capacity retention of 75.9% with a coulomb efficiency (C.E.) of 97.3% after 200 cycles. The MUF-CN cathode gives a specific capacity of 1335.6 mA h g−1 at 0.05 C, and the capacity retention of 66.7% with a C. E. of 93.6% after 300 cycles at 0.5 C. The SG-CN cathode had a specific capacity of 953.9 mA h g−1 at 0.05 C, and capacity retention of 95.1% with a C. E. of 98.2% after 125 cycles at 1 C. The remarkable improved performances were mainly ascribed to the sustainable materials as S host with micro-meso pore and C3N4 structure providing the strong affinity N sites to lithium polysulfides (LiPSs). This work provides an attractive approach for the preparation of sustainable materials by rational design of grafting C3N4 to waste-derived carbons with functions as S cathode materials for high-performance Li-S batteries.

The monodisperse manganese oxide nanoparticles with an average diameter of 30nm were chemically synthesized. The nanoparticles assembled as a close-packed monolayer on Pt bottom electrode by dip-coating and annealing process. The Ta/Ta2O5/MnO/Pt device was fabricated. The bipolar resistive switching behaviors could be caused by the formation and rupture of conductive filaments in the switching layers. The stable self-compliance property was demonstrated which can be attributed to the high resistance Ta/Ta2O5 interface, the Schottky barrier of Ta/Ta2O5, and the discontinuity of conduction band at Ta2O5 and MnO interface. The retention characteristics of Ta/Ta2O5/MnO/Pt device were investigated. The conduction mechanisms of Ohmic conduction, space charge limited conduction, Schottky conduction and Poole-Frenkel emission had been investigated for resistance switching mechanism. Display Omitted The resistive switching behaviors with heterostructure were demonstrated.The monodisperse oxide nanoparticles were chemically synthesized.The device showed bipolar switching and repeatable self-compliance properties.The bipolar switching was caused by the formation and rupture of conductive filaments in oxide layer.The stable self-compliance property was demonstrated.

In our study, the devices with Pt/Ti/TaOx/Pt, where x ranges from 1.34 to 1.47, Pt/Ti/HfO2/Pt and Pt/Ti/TaOy/HfO2/Pt were fabricated. The TaOx and HfO2 were the switching layers for single layer devices and for hybrid device TaOy acted as oxygen reservoir and HfO2 acted as switching layer. The single layer devices exhibited co-existence of bipolar and unipolar switching. For bipolar switching the SET process occurred when positive sweep voltage was applied and RESET process occurred for negative sweep. The transition from bipolar to unipolar was observed to be irreversible. The hybrid device exhibited the unipolar switching with two high resistance state (HRS) levels. Moreover, the conduction mechanism of ohmic conduction, space charge limited conduction (SCLC); Schottky conduction and Poole-Frenkel (P-F) conduction have been investigated. Display Omitted The resistive switching behavior of tantalum oxide, hafnium oxide and their hybrid devices are studied.The tantalum oxide and hafnium oxide monolayer devices exhibited co-existence of unipolar and bipolar switching.The transition from bipolar to unipolar switching is observed to be irreversible for the mono layer devices.The hybrid device with structure Pt/Ti/TaOx/HfO2/Pt presented only unipolar switching.The resistive switching was improved by the fabrication of hybrid device.

Lanthanum-based LaMO3 (M = Fe, Co, Ni) perovskite nanofibers were effectively fabricated by electrospinning approach coupled with calcination process. The crystallinity, microstructures, morphologies, elemental compositions, and chemical bonding states of LaMO3 perovskites were investigated in detail. The electrochemical properties of LaMO3 perovskite nanofibers as supercapacitor electrodes and lithium-ion battery anodes were elucidated. The specific capacitances of LaFeO3, LaCoO3, and LaNiO3 nanofibers were 183.6, 95.8 and 116.3 F g−1 at the current density of 1 A g−1, respectively. The supercapacitive properties of LaMO3 NFs had originated from the redox reactions of M3+/M2+. As lithium-ion battery anodes, LaMO3 (M = Fe, Co, Ni) nanofibers exhibited the specific discharge capacities of 331, 646, and 92 mAh g−1 after 200 cycles, respectively. This research endowed the potential and competent candidates of the perovskite type lanthanum-based nanofibers for supercapacitor electrodes and lithium-ion battery anodes.

Resistive switching behaviors in metal oxides have been mentioned for several decades. TiO2 is still a well-known material for resistive switching memory devices. The resistive switching characteristics of TiO2 thin films with different top electrodes were investigated. The devices had typical bipolar resistive switching behaviors. The resistance changed from a high-resistance state (low-resistance state) to a low-resistance state (high-resistance state) under positive (negative) sweeping voltage. The interface between the top electrode and the oxide layer could affect the resistive switching behaviors. The electrical properties of Metal/TiO2/Pt devices with different top electrodes showed different switching characteristics. The conduction mechanism of the devices was also investigated. In the low-resistance state, ohmic conduction was dominant. The conduction mechanism exhibited ohmic conduction at low voltages and space-charge-limited-conduction at high voltages in the devices of Cu/TiO2/Pt, Ni/TiO2/Pt and Al/TiO2/Pt, respectively. For Ta/TiO2/Pt Schottky conduction also played an important role.

Analog memristive and memcapacitive switching characteristics were investigated in Pt-Fe2O3 core-shell nanoparticles (NPs) assembly on p+-Si substrate. The Ti/NPs/p+-Si structure exhibited gradually changing resistance (memristive) and capacitance (memcapacitive) at the same time as repeating the application of voltage with respect to the polarity of voltage. As applying negative voltage at top Ti electrode, the resistance decreased and the capacitance increased due to the increase of diffusion capacitance at n-NPs/p+ -Si junction. On the other hand, applying the positive voltage increased resistance and decreased capacitance by increasing depletion width at the junction. The polarity-dependent resistance and capacitance changes are thought to be ascribed to the charging of the NPs assembly that alters the potential of the assembly. The concurrent analog memristive and memcapacitive characteristics also emulated the biological synaptic potentiation and depression motions, which is indicative of potential application to neuromorphic devices as well as analog nonvolatile memory and circuits.

The reflectivity and consequent color of anodic aluminum oxide (AAO) containing maghemite (γ-Fe 2 O 3 ) nanoparticles (NPs) were investigated. The hexagonally ordered pores of AAO were completely filled with maghemite NPs with ∼20 nm in diameter by the dip-coating process. The AAOs containing maghemite NPs have a reduced reflectivity of light at the wavelength below ∼600 nm, resulting in golden color. The reduced reflectivity and golden color of AAOs with NPs was explained by the absorption of light from blue to violet wavelength range by maghemite NPs. These results indicate the potential color-engineering of AAO by means of wavelength-selective absorption by incorporated NPs.

The resistive random access memory (RRAM) devices with heterostuctures have been investigated due to cycling stability, nonlinear switching, complementary resistive switching and self-compliance. The heterostructured devices can modulate the resistive switching (RS) behavior appropriately by bilayer structure with a variety of materials. In this study, the bipolar resistive switching characteristics of the bilayer structures composed of Ta

The fabrication of 3 x 3 crossbar arrays measuring 20 μm in width was demonstrated. The bipolar resistive switching characteristics in manganese oxide nanoparticles were investigated in the crossbar structure of top electrode (Au)/nanoparticle assembly/bottom electrode (Ti) on SiO2/Si substrate. The monodisperse manganese oxide nanoparticles measuring 13 nm in diameter were chemically synthesized by thermal decomposition of manganese acetate in the presence of oleic acid at high temperature. The nanoparticles were assembled as a layer measuring 30 nm thick by repeated dip-coating and annealing steps. The Au/nanoparticle assembly/Ti devices performed the bipolar behavior associated with the formation and sequential rupture of multiple conducting filaments in applying bias on Au electrode. When the voltage was swept from to +5 V to the Au top electrode, the reset voltage was observed at - 4.4 V. As the applied voltage swept from 0 to -5 V, the set voltage occurred at (-) -1.8 V.

The fabrication of 3 × 3 crossbar arrays with a width of 20 μm is demonstrated. The bipolar resistive switching characteristics in Pt–Fe 2 O 3 core–shell nanoparticles are investigated in the crossbar structure of top electrode (Au)/Pt–Fe 2 O 3 nanoparticle assembly/bottom electrode (Ti) on SiO 2 /Si substrate. The monodisperse Pt–Fe 2 O 3 nanoparticles with the diameter ∼15 nm are chemically synthesized by the preferential oxidation of Fe and then pileup of Pt into the core in the presence of oleic acid and oleylamine at high temperature. The nanoparticles are assembled as a layer with a thickness of 50 nm by repeated dip-coating. The Pt cores in the core–shell nanoparticles act as electron traps. The bipolar resistive switching behavior in Au/nanoparticle assembly/Ti device could be caused by the electron trapping and detrapping of the nanoparticles. The resistance ratio of HRS to LRS is ∼57 at a reading voltage of 0.5 V. The value of reset voltage is 3.4 V and that of set voltages is −1.0 V.

A controllable and reversible transition of volatile and non-volatile resistive switching is presented in Ag/indium-gallium-zinc oxide (IGZO)/manganese oxide (MnO)/Pt bilayer resistive memory devices. The coexistence of volatile and non-volatile switching characteristics was demonstrated by controlling the current compliance during the SET process. With lower current compliance (

Colloidal FePt–Fe2O3 core–shell nanoparticles (NPs) were chemically synthesized through a two-step process, where FePt NPs were synthesized first and then coated by a Fe2O3 shell. These NPs were attached on the carbon nanotubes (CNTs) by the hydrophobic and van der Waals interaction after the surface functionalization of CNTs in acetone. The NPs-attached CNTs exhibited the threshold switching from the high-resistance state to low-resistance state at a high voltage and vice versa at a low voltage, while the bare CNTs showed ohmic transport. From the conduction mode analysis, it turns out that the threshold switching results from enhanced charge transport by overcoming the energy barrier of Fe2O3 shell at a high voltage.

The secondary growth of carbon nanotubes (CNTs) on the surface of CNTs to form the chemically connected CNTs structure was investigated. In order to grow the secondary CNTs, the catalyst FePt nanoparticles (NPs) were chemically synthesized as colloids and attached on the primary CNTs through the hydrophobic interaction between CNT and NPs as dispersed inside the solution. It was demonstrated that a bunch of secondary CNTs could grow from multiple NPs on the single primary CNTs by chemical vapor deposition. These secondary CNTs were entangled each other between primary CNTs, which provide the possible high density network with chemically connected structure.

Resistive switching characteristics of maghemite (γ-Fe2O3) nanoparticle (NP) assembly were investigated in patterned array structure of Pt/γ-Fe2O3/Pt on a flexible polyethylene terephthalate (PET) substrate. The NPs layer was formed through dip-coating process. The cross-bar array patterned devices with NPs sandwiched between Pt electrodes exhibited memristive switching with hysteresis in current-voltage characteristics with gradually changing resistance with respect to the bias conditions.

Resistive switching characteristics of FePt/γ-Fe2O3 core- shell nanoparticle (NP) assembly on flexible substrate of polyethersulfone (PES) as being sandwiched by top and bottom Al electrodes were investigated for the potential as a flexible resistive switching memory. The NPs assembly was formed by solution process of dip-coating. The initial bipolar switching was observed in the voltage range < ±3 V, and the subsequent voltage sweep to higher voltage led to the increase of resistance, which is not typically observed in γ-Fe2O3 NP or other metal-oxide layer structure. Though the fundamental principle of resistive change in core-shell NPs is not clear, it demonstrated the feasibility of flexible memory application through solution-based processes.

The formation of a vertically and laterally self-aligned double layer of CdSe colloidal nanocrystals (NCs) in a nanopatterned dielectric layer on Si substrate was demonstrated by a repeating dip-coating process for NC deposition and atomic layer deposition (ALD) of Al 2 O 3 layer. A nanopatterned SiO 2 /Si substrate was formed by patterning with a self-assembled diblock copolymer. After the selective deposition of the first NC layer inside the SiO 2 nanopattern by dip-coating, an Al 2 O 3 interdielectric layer and the second NC layer in the Al 2 O 3 nanopattern were sequentially deposited. The capacitance-voltage measurement of an Al-gate/ALD-Al 2 O 3 (25 nm)/second-Cdse-NCS/ALD-Al 2 O 3 (2 nm)/first-CdSe-NCs/nanopatterned-SiO 2 (15 nm)/p-Si substrate structure showed the flatband voltage shift through the charge transport between the gate and NCs.

The fabrication of a manganese oxide and cerium oxide bilayer structure with a 5 × 5 crossbar array was demonstrated. The resistive switching characteristics of Ag/MnO/CeO2/Pt devices were investigated. The devices showed stable forming-free bipolar resistive switching properties with high resistance ratio (>105–6). Resistive switching phenomena were ascribed to the formation and rupture of oxygen-deficient conductive filaments. The mechanisms of ohmic and Schottky conductions were investigated to determine the resistance switching mechanism.

Tri-state resistive switching characteristics of bilayer resistive random access memory devices based on manganese oxide (MnO)/tantalum oxide (Ta2O5) have been studied. The current–voltage (I–V) characteristics of the Ag/MnO/Ta2O5/Pt device show tri-state resistive switching (RS) behavior with a high resistance state (HRS), intermediate resistance state (IRS), and low resistance state (LRS), which are controlled by the reset process. The MnO/Ta2O5 film shows bipolar RS behavior through the formation and rupture of conducting filaments without the forming process. The device shows reproducible and stable RS both from the HRS to the LRS and from the IRS to the LRS. In order to elucidate the tri-state RS mechanism in the Ag/MnO/Ta2O5/Pt device, transmission electron microscope (TEM) images are measured in the LRS, IRS and HRS. White lines like dendrites are observed in the Ta2O5 film in both the LRS and the IRS. Poole–Frenkel conduction, space charge limited conduction, and Ohmic conduction are proposed as the dominant conduction mechanisms for the Ag/MnO/Ta2O5/Pt device based on the obtained I–V characteristics and TEM images.

Improved resistive switching characteristics are demonstrated in a hybrid device with Pt/Ti/MnO (thin film)/MnO (nanoparticle)/Pt structure. The hybrid devices of MnO thin film and nanoparticle assembly were fabricated. MnO nanoparticles with an average diameter of ~30 nm were chemically synthesized and assembled as a monolayer on a Pt bottom electrode. A MnO thin film of ~40 nm thickness was deposited on the nanoparticle assembly to form the hybrid structure. Resistive switching could be induced by the formation and rupture of conducting filaments in the hybrid oxide layers. The hybrid device exhibited very stable unipolar switching with good endurance and retention characteristics. It showed a larger and stable memory window with a uniform distribution of SET and RESET voltages. Moreover, the conduction mechanisms of ohmic conduction, space-charge-limited conduction, Schottky emission, and Poole?Frenkel emission have been investigated as possible conduction mechanisms for the switching of the devices. Using MnO nanoparticles in the thin film and nanoparticle heterostructures enabled the appropriate control of resistive random access memory (RRAM) devices and markedly improved their memory characteristics.

The method of controlling dislocation positions via local oxidation of 80 nm thick Si 0.8 Ge 0.2 buffer layer on Si substrate is investigated. The strained SiGe layer is locally exposed to oxidation by patterning Si 3 N 4 mask layer on SiGe with perpendicularly crossing stripe patterns with directions. The local oxidation of patterned SiGe regions leads to increased stress to the remaining SiGe either via Ge pileup or volume expansion during oxidation. The increased stress in the SiGe region underneath the oxide increases dislocation nucleation rate. The preferential nucleation of dislocations and subsequent propagation of dislocations through non-oxidized regions results in reduced threading dislocation density to 10 6 – 7 /cm 2 , which is lower than that of the conventional constant composition SiGe buffer layer. Further reduction of threading dislocation density is expected by optimizing the oxidation conditions and pattern size and shape for local oxidation.

Carbon blacks could be used as the filler for the electromagnetic interference (EMI) shielding. The poly vinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) were used as the matrix for the carbon black fillers. Porous carbon blacks were prepared by CO2 activation. The activation was performed by treating the carbon blacks in CO2 to different degrees of burnoff. During the activation, the enlargement of pore diameters, and development of microporous and mesoporous structures were introduced in the carbon blacks, resulting in an increase of extremely large specific surface areas. The porosity of carbon blacks was an increasing function of the degree of burn-off. The surface area increased from 80 m2/g to 1142 m2/g and the total pore volume increased from 0.14073 cc · g−1 to 0.9343 cc · g−1. Also, the C=O functional group characterized by aldehydes, ketones, carboxylic acids and esters was enhanced during the activation process. The EMI shielding effectiveness (SE) of raw N330 carbon blacks filled with PVA was about 1 dB and those of the activated carbon blacks increased to the values between 6 and 9 dB. The EMI SE of raw N330 carbon blacks filled with PVDF was about 7 dB and the EMI SE increased to the range from 11 to 15 dB by the activation. Keywords : Electromagnetic interference shielding, Carbon black, CO2 activation, Poly vinyl alcohol, Polyvinylidene fluoride

Rubber reinforcing carbon black N330 was treated by physical activation under CO2 to different degrees of burn-off. The mechanical properties indicating the reinforcement of SBR (Styrene-Butadiene Rubber) vulcanizates filled by activated carbon blacks, such as tensile strength, modulus at 300% strain and elongation at break were determined. During CO2 activation of fresh carbon blacks, the development of microporous structure caused an increase of extremely large specific surface area and the porosity turned out to be an increasing function of the degree of burn-off. The tensile strength and modulus at 300% of activated carbon blacks filled rubber composites were improved at lower loading ratios of 20 and 30 phr, but decreased drastically after 30 phr, which is considered that it might be difficult to get a fully dispersed rubber mixture at higher loading ratios for fillers having very large specific surface areas. However, the Electromagnetic Interference (EMI) shielding effectiveness of SBR rubber composites having activated carbon black at 74% yield were improved at a large extent when compared to those having raw carbon black and increased significantly as a function of increasing loading ratio. Keywords : Carbon black, CO2 activation, Rubber reinforcement, EMI shielding effectiveness

To investigate the nature of the switching phenomenon at the metal-tantalum oxide interface, we fabricated a memory device in which a tantalum oxide amorphous layer acted as a switching medium. Different metals were deposited on top of the tantalum oxide layer to ensure that they will react with some of the oxygen contents already present in the amorphous layer of the tantalum oxide. This will cause the formation of metal oxide (MOx) at the interface. Two devices with Ti and Cu as the top electrodes were fabricated for this purpose. Both devices showed bipolar switching characteristics. The SET and RESET voltages for the Ti top electrode device were ∼+1.7 V and ∼−2 V, respectively, whereas the SET and RESET voltages for the Cu top electrode device were ∼+0.9 V and ∼−0.9 V, respectively. In the high-resistance state (HRS) conduction, the mechanisms involved in the devices with Ti and Cu top electrodes were space-charge limited conduction (SCLC) and ohmic, respectively. On the other hand, in the low-resistance state (LRS), the Ti top electrode device undergoes SCLC at a high voltage and ohmic conduction at a low voltage, and the Cu top electrode again undergoes ohmic conduction. From the consecutive sweep cycles, it was observed that the SET voltage gradually decreased with the sweeps for the Cu top electrode device, whereas for the Ti top electrode device, the set voltage did not vary with the sweeps.

The fabrication of hybrid structure with TiO2 nanoparticle assembly and Ta2O5 thin film layer was demonstrated. The close-packed nanoparticles could influence the resistive switching behaviors due to the huge numbers of interface states and vacancies in the nanoparticle assembly. The device with hybrid structure presented the typical bipolar resistive switching characteristics in the structure of Ti/TiO2/Ta2O5/Au on SiO2/Si substrate. The set voltage was observed at -0.7 V, and the reset voltage occurred at (-)-0.7 V, which was smaller than that of Ta2O5 layer only. The electrical conduction mechanisms were the ohmic conduction at low resistance state (LRS) and the space charge limited conduction at high resistance state (HRS), respectively. The devices showed stable current ratio of LRS to HRS. The temperature dependent properties of the devices were also investigated. The device with nanoparticle assembly showed better electrical characteristics with low HRS current level and stable LRS current level with respect to the temperature.

Carbon/silicon composites were synthesized by mixing silicon powders with petroleum pitch and subsequent heat-treatment. The resultant composites were composed of carbon and nano-size crystalline silicon identified by XRD and EDX. FIB images and SEM images were taken respectively to detect the existence of silicon impregnated in carbon and the distribution of silicon on the carbon surface. The obtained carbon/silicon materials were assembled as half cell anodes for lithium ion secondary battery and their electrochemical properties were tested. The pitch/silicon composite (3 : 1 wt. ratio) heat treated at 1000℃ and mixed with 55.5 wt.% of graphite showed relatively good electrochemical properties such as the initial efficiency of 78%, the initial discharge capacity of 605 mAh/g, and the discharge capacity of 500 mAh/g after 20 cycles.

Strength reliability and thermal stability of SiC/SiC composites are important as structural candidates for nuclear fusion reactor. Several CVI-Tyranno-SA (plain-woven)/SiC composites were fabricated and the flexural strength and the effects of the high temperature heat treatment in vacuum were investigated. The flexural strength and statistical properties of the as-fabricated composites showed a dependence on composite density. The highest average strength, 640 ± 69 MPa, with the highest Weibull modulus, m=12.2, was obtained by the composite with the highest density among the several composites. No significant change of the strength of the composite was noticed against heat treatment at temperature up to 1973 K in vacuum of ∼3 × 10−4 Pa for 1 h, beyond which the strength decreased with the increasing of the heat treatment temperature.

A SiC nanowire/Tyranno-SA fiber-reinforced SiC/SiC composite was fabricated in situ. Mechanical behaviour during three-point bending were examined. The composite showed marked improvements on the flexural strength and work of fracture compared with a group of conventional Tyranno-SA/SiC composites. Web-like structures, formed from the original SiC nanowires in the composite, were readily observed within the fiber bundles that were not fully deposited with matrix. These web-like structures likely served as reinforcements together with the Tyranno-SA fibers, which provided additional strength and fracture tolerance in the composite.

SiC nanowires over 10 μm in length and 20–100 nm in diameter have been synthesized by a novel in situ chemical vapor growth process on RS-SiC plates. The SiC nanowires were identified as single crystal β-SiC with Si–C chemistry. The growth direction of the nanowires is 〈1 1 1〉. The growth mechanism is discussed and a kinetic vapor–solid growth mechanism is proposed. The process demonstrates the possibility to fabricate SiC nanowires in ceramic matrix composites, such as continuous SiC fibers reinforced SiC matrix composites, with the SiC nanowires uniformly dispersed in the matrix.

A modified thermal evaporation processing is reported to fabricate silicon nanowires starting from Si powder under normal pressure. In a temperature range of 1250–1290 °C, long single-crystal Si nanowires with an amorphous layer were grown in relative large quantity, and they had a millimeter-scale length and a uniform diameter of about 100 nm. A high-resolution transmission electron microscopy image indicated that the growing direction of the long Si nanowires is [111].

An IR absorption measurement of SiO 2 /Si nanowires made by thermal evaporation was conducted. In comparison with SiO 2 nanoparticles, enhancement absorption of SiO 2 /Si nanowires around 1130 cm −1 was observed. This enhancement was considered to result from: (1) the interface effect of the open structure of chainlike SiO 2 /Si nanowires; (2) the vibration of an interstitial oxygen atom in a silicon single-crystalline core of nanowire; and. The longitudinal optical (LO) modes of Si–O–Si stretching in an amorphous SiO 2 outer shell of SiO 2 /Si nanowires were also discussed.

A SiC/SiC composite in a disc preform of 120 mm in diameter and 3.2 mm in thickness was fabricated by the chemical vapor infiltration (CVI) process. The composite was reinforced with plain-woven high-crystalline Tyarnno-SA fiber. Microstructure examinations and density measurements indicated a quite dense and very good space homogeneous matrix deposition in the composite. The fracture behavior and statistic reliability of the flexural strength upon three-point bending loading were investigated. The composite had an average flexural strength 597 MPa with a standard deviation 70 MPa. The statistic analysis of the strength showed good consistency among the bending specimens, with a Weibull modulus of 10.2, which is much higher than that for the Nicalon and Hi-Nicalon fibers reinforced CVI-SiC matrix SiC/SiC composites.