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Metal oxide semiconductor (MOSC) sensors based on nanocrystalline MoO3, In2O3, and their composites are considered to be very sensitive to detect low concentrations of ethanol, ozone, hydrogen, formaldehyde, and nitrogen dioxide. Here, we firstly introduced In2(MoO4)3 phase, which has excellent negative thermal expansion and high electric conductivity properties, into In2(MoO4)3@In2O3 crystalline nanocomposites. The gas-sensing performance of the In2(MoO4)3@In2O3 nanocomposites was studied upon exposure to the ethanol gas with different concentration from 5 to 300 ppm at the optimum temperature (300 °C). What's more, the device possesses ultra-high response of 110 and selectivity to ethanol. Particularly, it can effectively work in high humidity (RH = 80%) with super long-term stability of as long as 90 days, compared with the pristine In2O3 sensor and previous reports. The presented novel In2(MoO4)3@In2O3 sensor offers great opportunities for future ethanol detection under harsh conditions.

High-pressure torsion (HPT) is a severe plastic deformation technique where a sample is subjected to torsional shear straining under a high hydrostatic pressure. The HPT method is usually employed to create ultrafine-grained nano-structures, making it widely used in processing many kinds of materials such as metals, glasses, biological materials, and organic compounds. Most of the published HPT results have been focused on the microstructural development of non-magnetic materials and their influence on the mechanical properties. The HPT processing of magnetic materials and its influence on the structural and magnetic properties have attracted increasing research interest recently. This review describes the application of HPT to magnetic materials and our recent experimental results on Mn3O4, Mn4N, and MnAl-based alloys. After HPT, most magnetic materials exhibit significantly reduced grain size and substantially enhanced coercivity.

Spinel nickel ferrite (NiFe 2 O 4 ) nanoparticles with high specific area and excellent magnetic properties were synthesized via a template-assisted sol – gel method. The effects of template type on the structural properties, magnetic properties, and heating rate are investigated. Results of XRD and TEM indicate that the NiFe 2 O 4 particles synthesized using templates exhibit a typical single phase spinel structure in nano size. The sample using sponge or cotton as template presents the best saturation magnetization (66.6 emu/g) and the lowest coercivity (137.7 Oe), respectively, and their specific surface area is enhanced greatly from 20.1 m 2 /g to 55.7 m 2 /g. It is found that the calculated hysteresis loss agrees well with the measured radio frequency heating rate.

Porous anodic alumina has been obtained through anodic oxidation in a mixed solution of sulfuric and citric acid. We investigated the microstructure and morphology of 2024 aluminum after being anodically oxidized under different voltage and temperature. Hardness and corrosion resistance of anodized aluminum has been also investigated. The results show that after anodization, many nanoholes appeared on the surface layer of the coating. Thickness of the anodized film increased from 2.7μm to 26.3μm with the voltage changing from 10 V to 18 V. Aodized films with the thickness of 18μm could be obtained under the temperature of 47°C. When the oxidation voltage is 12V, the hardness of the oxidation film reached 126HV. Maximum hardness (130 HV) could be achieved when the oxidation temperature was 57°C. After being dealt with in the NaCl solution, the electrochemical corrosion resistance of the anodic film got a sharp increase, and the anodic oxidation voltage had a great impact on the anodized film. When the oxidation voltage was 16V, the corrosion resistance of the film reached the highest value and the corrosion voltage was-0.7V. From the polarization curves, it has been found that the films obtained under the temperature of 37°C possessed more positive corrosion potential (-0.73V) and optimal anticorrosion performance.

Ceramic powders with chemical formula Eu4Ti3O12 were fabricated by sol-gel method. A milk-white homogeneously mixed gel was prepared, and transferred into a porous resin intermediate through charring. Eu4Ti3O12 powders were prepared by calcination of the resin intermediate, and ceramic samples with two phases of Eu2TiO5 and Eu2Ti2O7 were got by sintering. Meanwhile, the crystal structure was determined by X-ray diffraction and grain character was analyzed by scanning electron microscope. Eu4Ti3O12 ceramics has good microwave dielectric characteristics: εr=27.51, Qf=9450 GHz, τf=211 ppm/°C.

ZnO nanorods and nanoparticles were successfully modified by NDZ-311w titanate coupling agent. The result of lipophilic degree showed that both ZnO nanocrystals with different morphologies were well lipophilic. Although both values of lipophilic degree firstly became larger and then smaller with the increase of modifier dosage, the different maximal lipophilic degree of ZnO nanorods and nanoparticles could be 68.8% and 77.9%, respectively. By comparing the two curves of lipophilic degree of surface modified ZnO nanocrystals with different morphologies, it could be demonstrated that the optimal dosage of NDZ-311w titanate coupling agent is inversely proportional to the grain size. TEM and XRD results showed that the grain size of ZnO nanoparticles were much smaller than that of ZnO nanorods, which can be the evidence for the equation. Otherwise, the surface modified ZnO nanoparticles displayed better dispersion than unmodified ones.

New compounds of sodium samarium titanate Na0.5Sm4.5Ti4O15and sodium europium titanate Na0.5Eu4.5Ti4O15were synthesized successfully by solid state reaction at 1300 oC and 1200 oC, respectively. The lattice parameters of Na0.5Sm4.5Ti4O15and Na0.5Eu4.5Ti4O15were determined at ordinary temperature by using X-ray powder diffraction method. Their Lattice types were determined, and their patterns were indexed. Polycrystalline X-ray diffraction data of sodium samarium titanate were listed. Differences of their crystal structures were analyzed and discussed.

Novel nano-composite powders composed of hard-magnetic Mn54Al46 and soft-magnetic α-Fe were prepared by high-energy ball milling. The effect of α-Fe and preparation conditions on the structure and magnetic properties of the composite powders has been investigated. The ε-MnAl transforms to γ-MnAl, τ-MnAl, and β-phase under ball milling and annealing. The saturation magnetization and coercivity of the two-phase samples decrease with increasing temperature for the τ-phase decomposes at elevated temperatures. With increasing iron content, the coercivity decrease first and then increase up to 0.33 T when the Fe content is 10 wt%. Further addition of the magnetically soft iron phase would result in a decrease of the coercivity.

The recoil behavior of melt-spun ribbons of Zr-doped α-Fe/Nd2Fe14B alloys has been investigated by analyzing hysteresis curves and recoil loops of demagnetization curves. A drastic increase of the coercivity Hc from 620kA/m to 855kA/m at room temperature by an addition of 1at.% Zr in α-Fe/Nd2Fe14B alloys has been observed. According to integrated recoil loop area, it is found that the maximum value of the integrated recoil area for Zr-doped sample (3.05 kJ/m3) is significantly lower (about 7 times) than that value for the Zr-free sample (20.9 kJ/m3). The reason of reduced recoil loop area in high coercivity α-Fe/Nd2Fe14B nanocomposite alloys by Zr addition was discussed in term of the process of irreversible magnetization reversal also.

The effects of Zr addition on the microstructure and magnetic properties of the sintered NdFeB magnets were investigated by X-ray diffraction (XRD) and BH magnetic tester. The XRD analysis showed that both the Zr-free and Zr-doped samples are composed of main amount of Tetragonal phase Nd2Fe14B (P42/mnm) and trace amount of Nd-rich phase, but adding Zr reduces significantly the values of pole density factor of (004), (006) and (008) crystal faces for the sintered Nd(Fe,Zr)B magnets estimated by Horta-formula. Accordingly, the coercivity of the sample with Zr addition is reduced from 2038 kA/m down to 1951 kA/m. The study of the Kronmüller-plot shows that the nucleation is the dominating mechanism for the magnetization reversal in these two kinds of magnets, and two microstructural parameters of αk and Neff are obtained also.

Magnetic fluid is a stable colloidal dispersion of ferromagnetic particles in a liquid carrier. Once a magnetic field is applied to magnetic fluids (MF), various structures of MF are formed. A detailed understanding of structures and particle distributions in gradient magnetic fields is much important. But very few works have been done on this. In the present study, the effects of magnetic field gradient and magnetic interaction among magnetic particles on the structures of MF are investigated using a two-dimensional Monte Carlo simulation. The results show that a gradient distribution of magnetic particles is formed under gradient magnetic fields. However, as the interaction between magnetic particles increases, the distribution gradient decreases, accompanied by the formation of chain-like clusters. Moreover, with increasing the magnetic interaction, particle distribution changes from grass-like clusters to needle-like ones.

When a magnetic field is applied to magnetic fluids (MF), various structures of MF are formed: chain-like structures in low fields, columnar, lamellar and striped structures in high fields, ellipsoidal structures in pulsed fields, and layered structures in rotating fields. The inner structures and particle distributions of MF in gradient magnetic fields are quite interesting, but very few works have been done on this. In the present study, the effects of magnetic field gradient on the structures of MF are investigated using a two-dimensional Monte Carlo simulation. The results show that a gradient distribution of magnetic particles is formed under gradient magnetic fields. Moreover, with increasing the field gradient, more magnetic particles are pushed to the right region and particle distribution changes from grass-like clusters to needle-like ones.

Functionally graded materials (FGMs) have recently been fabricated under gradient magnetic fields via slip casting, based on the distinct difference in magnetic susceptibility between the components in a suspension comprised of both magnetic particles (MPs) and nonmagnetic particles (NPs). In this work, a physical model of a mixed suspension comprised of both MPs and NPs under a gradient magnetic field is built, base on which the distributions of particles in the suspension under gradient magnetic fields are studied using two-dimensional Monte Carlo simulations, and the effects of magnetic field gradient on the distributions of particles are investigated. The results show that a gradient distribution of MPs is formed along field direction, which is attributed to the translation of MPs. As the magnetic field gradient is increased, the distribution gradient of MPs increases.

By using the extended hyperbolic function approach, we explore the discrete (2 + 1)-dimensional Toda lattice and the discrete Hybrid lattice, and successfully obtain some new exact soliton solutions, including the discrete kink-type soliton solution, bell-type soliton solution and some other types of soliton solutions.

In order to investigate the influence of the arrangement of the carbon nanotubes (CNTs) array on the field emission, the more practical model in hexagon was proposed. From the calculation with the image floated sphere model, the results showed that the arrangement has little influence on the field emission and the intertube distance R of CNTs array critically affects the field emission from the CNTs array, which accords with the results from the numerical simulations and experiments. When R is less than the height of tube h , the enhancement factor decreases rapidly with R . Considering the field emission current density, the field emission can be optimized when R is comparable with h , which accorded with the results from experiments. Furthermore, the influence of the anode–cathode distance d on the field emission from CNTs array was also discussed, which proved that d has little effect on the field emission from CNTs array. For the fixed field strength E for the certain materials in filed emission, we can reduce the threshold voltage to some extent by decreasing d in the case of R > 2 h .

We present a magnetic force microscopy and atomic force microscopy study of magnetic and crystalline microstructures of melt-spun binary Fe 50+ x Pt 50− x ( x= 0−20) and ternary (Fe 0.5+ y Pt 0.5− y ) 82 B 18 ( y= 0−0.2) nanocomposite ribbons. It was confirmed that an ordered magnetically hard γ 1 -FePt phase could be fully formed at x⩽ 10 in Fe 50+ x Pt 50− x ribbons. From the topographic images of the Fe 50+ x Pt 50− x and (Fe 0.5+ y Pt 0.5− y ) 82 B 18 ribbons, it was found that the average crystal size D ¯ is large (∼1.1–3.9 μm) for the Fe 50+ x Pt 50− y ribbons without B, but that of the (Fe 0.5+ y Pt 0.5− y ) 82 B 18 ribbons with invariable B content is much small ( ∼ 57–65 nm). Moreover, the magnetic force images with distinct contrast could be detected by MFM only in the ribbons with strong exchange-coupling interaction. Finally, it was found that for exchange-coupling nanocomposite ribbons, the strength of the exchange-coupling interaction can be reflected roughly by the root-mean-square roughness of phase shift, ( Δ φ ) rms , of magnetic force images and the ratio of the average domain width w ¯ to the average crystal size D ¯ .

The growth mechanism and characteristic ordered patterns of iron (Fe) films deposited on the silicone oil surfaces by a DC-magnetron sputtering method are presented in this paper. It is found that as the film thickness increases, the iron atoms deposited on the oil surface first form compact clusters, then transfer to ramified aggregates and web-shaped structures, and finally form a continuous iron film. The average branch width of the ramified aggregates is about 0.34 μm, which is almost independent of the sputtering power, i.e., the deposition rate. In the continuous iron films, large spatially disk-shaped patterns are observed, which result from spontaneous ordered organization of the iron atoms and atomic clusters driven by the internal stress in this nearly free sustained film system.

In this paper, we present the spontaneous formation of an unusual type of ordered structures in thin metal film systems deposited on silicon oil surfaces by a thermal evaporation method. These structures are composed of a large number of parallel rectangular-shaped domains and exhibit anti-symmetric characteristic. The experiment shows that thin solid films can move freely on liquid surfaces due to the near-zero adhesion of the solid–liquid interface, resulting in superposition of the films and formation of the ordered structures. Compressive stress gradient in the films is shown to be the driving force for self-organization. All characteristics of the ordered structures are discussed in detail based on special mechanical behaviors of these near-free sustained films.

The growth behavior and surface morphology of a rough film system, deposited on silicone oil drop surfaces by a r.f. magnetron sputtering method, have been studied. An anomalous film growth relaxation is observed during the deposition process. The relaxation rate is extremely sensitive to the substrate temperature. The surface morphology at the micrometer length scale is very susceptible to the substrate temperature, the incident r.f. capacity, and the nature of the solid substrate on which the oil drop is dripped. A discussion on the physical origins of these phenomena is also presented.

Preparation of a metallic diffuse-fringe film system and its electrical properties are reported. The anomalousR-I characteristics, third-harmonic coefficient and critical behavior are observed in the film system. Analysis shows that this behavior is caused by the location-dependent tunneling and hopping effects, which result from. the continuous variation of the diffuse fringe structure of the film due to the increase of the current.

A rough-thin-film system, deposited on silicone oil drop surfaces by a rf-magnetron sputtering method, has been fabricated and its structure as well as I-V characteristics have been studied. A characteristic surface morphology at the micrometer scale is observed. The anomalous deposition rate, which strongly depends on the nominal film thickness, can be interpreted under the assumption of the second evaporating and the penetrating effects. We find ${\mathit{I}}_{\mathit{c}}$\ensuremath{\propto}${\mathit{R}}_{0}^{\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\alpha}}}$, with \ensuremath{\alpha}=0.52\ifmmode\pm\else\textpm\fi{}0.06, where ${\mathit{R}}_{0}$ and ${\mathit{I}}_{\mathit{c}}$ are the zero power resistance and the breakdown current, respectively. The importance of the liquid substrates is discussed. \textcopyright{} 1996 The American Physical Society.

We have fabricated a metallic diffuse-fringe film system by dc-magnetron spulleririg method. The diffuse fringe structure of the film system is obviously observed when during the film deposition process the distance between the shutter slit and the substrate is large enough. An anomalous, nonlinear I-V behavior is found in the system and can be well explained by the Joule heating and hopping effects. The strong dependence between the conductivity behavior and the fringe indicates that the fringe effect is very severe in this inhomogeneous percolation system.

A wedge-shaped Pt-film percolation system was prepared by the magnetron sputtering method. A new nonlinear I-Vbehavior was found and can be well explained by the location-dependent hopping effect. Power-law behavior, σ(ω) α ωx and ϵ(ω) α ω−y, is observed near the percolation threshold. The exponents x and y are found to be 0.87±0.04 and 0.08±0.03, respectively, in agreement with the general scaling relation x + y = 1.

Amorphous FexCu1-x thin films with x ranging from 0.21 to 0.81 have been obtained by rf-magnetron sputtering. The structure and the electric transport properties of the films can be controlled by both the composition and annealing temperature. The resistances of the films decrease with the temperature increasing from 12 to 300 K, which is the typical semiconductor characteristic. After annealing at 400° C for 5h, the amorphous FexCu1-x thin film is crystallized and exhibits electric transport property an normal metal film. The dependence of resistance-temperature characteristics of the films on the composition and deposition time is described.

The microstructure and the growth mechanism of the films, which were deposited on silicone oil surfaces by the rf-magnetron sputtering method, were studied systematically. It is found that, at the fixed incident rf capacity, the growth rate is not a constant and it depends on both the nominal film thickness and the substrate temperature. The film structure at the micrometer scale is highly sensitive to the substrate temperature. The dc resistance of the film increases with the increase of time, indicating that the behavior of the defects in the film is much different from that of the film deposited on a solid substrate. The effects of the liquid substrate are also discussed.

A new Ag rough film system, deposited on silicone oil surfaces by rf-magnetron sputtering method, has been fabricated. The chrysanthemum-like surface morphology at micron length scale is observed. It is proposed that the anomalous critical behavior mainly results from the relative shift between the Ag atom clusters and the substrate. The discussion of the deposition mechanism is also presented.

Systematic studies of the transport properties of La0.67Ca0.33Mn1−xFe x O3 (x=0–0.3) systems showed that with increasing Fe-doping contentx the resistance increases and the insulator-metal transition temperature moves to lower temperature. For small doping content, the transport property satisfies metal transport behavior below the transition temperature, and above the transition temperature it satisfies the small polaron model. This behavior can be explained by Fe3+ doping, which easily forms Fe3+−O2−−Mn4+ channel, suppressing the double exchange Mn3+−O2−−Mn4+ channel and enhancing the spin scattering of Mn ions induced by antiferromagnetic clusters of Fe ions.

The entanglement of formation of bipartite quantum Gaussian state is investigated by means of local operation, which maps continuous variable state to a bipartite qubits system. A two parameters quantum Guassian state is introduced, the concurrence of its mapped qubits state is calculated to characterize the entanglement of the original state.