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Summary Background Every year many adults aged 65 and over, suffer falls. This study used longitudinal data to investigate the long-term trend of falls among the elderly in Taiwan, and the association between falls and the utilization of medical facilities. Methods This study included 1653 elderly adults who completed questionnaires for a nationwide survey at different times. The data were analyzed with Chi-square test, independent-sample t-test, one-way ANOVA, Scheffe's post-hoc analysis and Generalized Estimating Equations (GEE), using SPSS 19.0 and Stata version SE 11.0. Results The proportion of elderly who had fallen has been increased 1.6 times from 1999 to 2007. The probability of using the traditional Chinese medicine (TCM) clinics (RR = 1.44) for those who had fallen was higher, as well as these of using the ER (RR = 1.81) and hospital (RR = 1.89), and the number of days hospitalized (RR = 1.85). There was no significant difference in their use of western medicine clinics (P > 0.05). Conclusion The government should provide appropriate medical care and services to reduce the incidence of falls in elderly and their uses of medical resources, thus improving elderly adults' quality of life.

Electrical conduction mechanism and bipolar resistive switching properties of the manganese oxide thin films resistive random access memory (RRAM) devices for high resistive status and low resistive status (HRS/LRS) were investigated and discussed. The electrical and physical properties of post-treatment manganese oxide thin films for different oxygen concentration parameters were measured by x-ray diffraction (XRD) and operation current versus applied voltage ( I-V ) measurement. For I-V curves in different temperature, the ohmic conduction, space charge limited conduction (SCLC), schottky emission conduction, and hopping conduction mechanism of manganese oxide RRAM devices were discussed and verified in initial metallic filament path forming process. Finally, the excess oxygen ions, vacancy, and defect factor resulting in bipolar and unipolar resistive switching behavior of thin films RRAM devices will be explained and investigated by metallic filament path forming model.

The bipolar switching properties and electrical conduction mechanism of vanadium oxide thin-film resistive random-access memory (RRAM) devices obtained using a rapid thermal annealing (RTA) process have been investigated in high-resistive status/low-resistive status (HRS/LRS) and are discussed herein. In addition, the resistance switching properties and quality improvement of the vanadium oxide thin-film RRAM devices were measured by x-ray diffraction (XRD) analysis, x-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and current–voltage (I–V) measurements. The activation energy of the hopping conduction mechanism in the devices was investigated based on Arrhenius plots in HRS and LRS. The hopping conduction distance and activation energy barrier were obtained as 12 nm and 45 meV, respectively. The thermal annealing process is recognized as a candidate method for fabrication of thin-film RRAM devices, being compatible with integrated circuit technology for nonvolatile memory devices.

This paper investigates the characteristics of applying indium–tin oxide (ITO) with and without nitride gas (N2) as the insulator in resistive random access memory (RRAM). After cosputtering an ITO target with N2 as the insulator and capping the same ITO material as the top electrode, the device exhibits rectifier and resistance switching characteristics before and after the forming process, respectively. The Schottky diodelike rectifier mechanism was also verified by various temperature measurements. Furthermore, robust resistance switching at a positive forming voltage, smaller than that required during negative bias forming, can be achieved. Both positive and negative forming processes are examined with current fitting results, which show different dominant mechanisms when using positive or negative biases. All these mechanisms have also been verified by temperature effect experiments, which confirmed the dominant conduction mechanisms. This, in combination with the fact that the positive forming voltage itself is smaller than the negative forming voltage, and decreases with device scale down, provides two highly beneficial results. This good performance achieved by using ITO with N2 suggests significant progress of RRAM and remarkable potential applications.

In this paper, indium-tin-oxide (ITO) was used to act as both insulator and top electrode in resistive random access memory (RRAM) on identical bottom substrates. This is achieved by cosputtering an ITO target with nitride (N2) or oxygen (O2) gas as the insulator; then capping by an ITO electrode, such that both the rectifier and RRAM characteristics can be achieved before and after a forming process, respectively. In contrast, using pure ITO as an insulator does not exhibit RRAM behavior. To verify the rectifier and RRAM characteristics, material analyses and electrical measurements at various temperatures were conducted. Reliability tests including retention and endurance were also applied to verify the resistance switching stability. Finally, the rectifier and RRAM conduction models were proposed to examine the resistance switching behaviors. By applying the ITO material as both electrode and insulator, the resistance switching characteristic with high reliability is thus obtained.

We have performed the fabrication and characterization of resistive random access memory devices based on Au/ZnO nanowires/Ag capacitor structure. First, vertically aligned ZnO nanowires were grown on Ag electrode layer. The poly 4-vinyl phenol (PVP) was then spin-coated on nanowires as a support and isolation layer. After appropriate etching of PVP in oxygen plasma to expose ZnO nanowire tips, a layer of Au was sputtered onto the tips of ZnO nanowires forming the top electrode. The resulting ZnO nanowire array devices were found to exhibit bipolar resistive switching characteristics. Switching between high resistance state (HRS) and low resistance state (LRS) could be achieved at a very low threshold voltage of 0.3 V for a long conducting channel of 500 nm, exhibiting a very low electric field, without electrical forming. The resistance ratios of HRS to LRS were higher than two orders of magnitude. The results indicate the application potentials of Au/ZnO nanowires/Ag devices for nonvolatile memory devices.

This letter investigates the double-ended resistive switching characteristics of indium tin oxide (ITO) resistance random access memory (RRAM). Resistive switching can be achieved around both the active TiN electrode and the inert Pt electrode. In addition, complementary resistance switching (CRS) characteristics can be observed without current compliance during dc voltage sweep operations. Electrical measurement data fitting results indicate that the oxygen-rich ITO near top and bottom electrodes works as a double-ended resistive switching layer. Based on the analysis of the current conduction mechanism, we propose a physical model to interpret the CRS behaviors in ITO RRAM devices.

Pr-doped ZnO thin films (Zn1−xPrxO) (x = 0.00, 0.01, 0.02, 0.04) were prepared on fluorine-doped tin oxide substrates by means of the sol–gel method and spin coating technology, followed by rapid thermal annealing treatment at 800 °C. The influence of Pr content on the structural and optical properties of the Zn1−xPrxO thin film was examined and discussed. The wurtzite hexagonal structural characteristics were investigated by X-ray diffraction analysis, and Pr3+ substitution for Zn2+ ions was indicated. Finally, the typical bipolar current-voltage switching curves and electrical conduction model of Zn1−xPrxO film resistive random access memory devices were discussed and investigated for low resistance state/high resistance state in the initial forming process.

In this study, a series of Li0.058(K0.480Na0.535)0.966(Nb0.90Ta0.10)O3 + (x)LiF (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5 wt%) lead-free piezoelectric ceramics were fabricated by a conventional solid-state reaction method. The incorporation of LiF could significantly improve the sintering ability of LKNNT ceramics by reducing the optimal sintering temperature from 1090°C to 1020°C. The crystal phases and micro-structures were analyzed by means of the X-ray diffraction and scanning electronic microscopy, respectively. The impedance analyzer was used to measure the Curie temperature, phase transition point, and electro-mechanical coupling factor. And the d33 meter was used to measure the piezoelectric constants.From the results, due to the addition of 0.2 wt% LiF, uniform and condensed grains can be obtained and hence the sintering temperature can be lowered down. As the contents of LiF increased, the orthorhombic to tetragonal phase transition points TO-T were almost no changed, but the Curie temperature TC ...

By the conventional solid-state liquid-phase sintering technique, Li0.058(K0.480Na0.535)0.966(Nb0.9Ta0.1)O3 + x wt% ZnO (x = 0, 0.2, 0.4, 0.6, 0.8, 1, 3) lead-free piezoelectric ceramics were fabricated. The addition of ZnO liquid-phase sintering promoters could improve the grain-growth of LKNNT ceramics significantly and its inferences were investigated detailed in this paper. The crystal phases and micro-structures were analyzed by means of the X-ray diffraction and scanning electronic microscopy, respectively. Using the impedance analyzer, the dielectric constant, loss tangent, Curie temperature, phase transition point, and electromechanical coupling factor were measured. And the piezoelectric constants were measured by the d33 meter. Compared to pure LKNNT ceramic (sintered at 1090°C, d33 = 279 pC/N, and kp = 0.46), for x = 0.6 specimen, even though the optimal d33 and kp values were only 272 pC/N and kp = 0.44, but the optimal sintering temperature have been improved from 1090°C to 1020°C suc...

By the radio frequency (RF) magnetron sputtering methods, (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 (BSTZ) ferroelectric thin films were deposited on the Pt/Ti/SiO2/Si(100) substrates. The crystal structural and microstructure of these thin films were analyzed by means of the XRD, SEM, and AFM. Moreover, the dielectric characteristics were also investigated by the C-V and J-E analyses. The optimal deposition parameters for these BSTZ thin films were: RF power is 160 W, oxygen concentration is 25%, substrate temperature is 580°C, and chamber pressure is 0.075 mPa. Under these optimal deposition conditions, the (111) and (110) oriented polycrystalline of the BSTZ thin films grow easily. And under a bias voltage of 0.5 MV/cm, the dielectric constant and leakage current density of the BSTZ thin films are 191 and 3×10−8 A/cm2, respectively. In addition, under various measured temperatures (0 ∼ 80°C) and frequencies (100 kHz ∼ 1 MHz), all the dielectric constants remain almost unchanged. Compared to BSTZ thin films re...

Bipolar switching properties and electrical conduction mechanism in Sn:SiO X thin-film RRAM devices were investigated and discussed. To complete the resistive switching properties of the stannum doped into silicon oxide thin films, the RTA-treated Sn:SiO X thin-film RRAM devices were investigated and discussed. In addition, the improvement qualities and electrical switching properties of the RTA-treated Sn:SiO X thin-film RRAM devices were carried out XPS, FT-IR, and IV measurement. The ohmic conduction with metal-like behavior and hopping conduction dependent activation energy properties by the Arrhenius plot equation in LRS of the Sn:SiO X thin films was investigated. The activation energy and hopping distance for the RTA-treated thin films were found to be 0.018 eV and 1.1 nm, respectively. For the compatibility with the IC processes, the RTA treatment was a promising method for the Sn:SiO X thin-film RRAM nonvolatile memory applications.

Bipolar resistive switching properties and endurance switching behavior of the neodymium oxide (Nd2O3) thin films resistive random access memory (RRAM) devices for a high resistive status/low resistive status (HRS/LRS) using a low temperature supercritical carbon dioxide fluid (SCF) improvement post-treatment process were investigated. Electrical and physical properties improvement of Nd2O3 thin films were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and current versus voltage (I-V) measurement. The metal-like behavior of ohmic conduction mechanism and metallic cluster reaction of hopping conduction mechanism in initial metallic filament path forming process of the SCF-treated thin films RRAM devices was assumed and discussed. Finally, the electrical conduction mechanism of the thin films RRAM derives for set/reset was also discussed and verified in filament path physical model.

Bi0.8Pr0.2Fe0.95Mn0.05O3/Bi3.96Gd0.04Ti2.95W0.05O12 (BPFMO/BGTWO) bilayer thin films with Multiferroic/Ferroelectric (MF/FE) structures were deposited onto Pt(111)/Ti/SiO2/Si(100) substrates by using the sol-gel method with rapid thermal annealing. The BPFMO/BGTWO thin films exhibited well-saturated ferromagnetic and ferroelectric hysteresis loops because of the electro-magnetic coupling induced by the MF/FE structure. The remnant magnetization (2Mr) and remnant polarization (2Pr) were 4.6 emu/cm3 and 62 μC/cm2, respectively. Moreover, the bipolar I-V switching curves of BPFMO/BGTWO bilayer thin films resistive random access memory (RRAM) devices were discussed, and investigated for LRS/HRS.

By the conventional solid state reaction method, a small amount of lithium fluoride (LiF) was used as the sintering promoter to improve the sintering and piezoelectric characteristics of (Ba0.95Ca0.05)(Ti0.93Sn0.07)O3 (BCTS) lead-free piezoceramic sheets. Using X-ray diffraction (XRD) and a scanning electron microscope (SEM), the inferences of the crystalline and surface microstructures were obtained and analyzed. Then, the impedance analyzer and d33-meter were used to measure the dielectric and piezoelectric characteristics. In this study, the optimum sintering temperature of the BCTS sheets decreased from 1450 °C to 1390 °C due to LiF doping. For the 0.07 wt % LiF-doped BCTS sheets sintered at 1390 °C, the piezoelectric constant (d33) is 413 pC/N, the electric–mechanical coupling coefficient (kp) is 47.5%, the dielectric loss (tan δ) is 3.9%, and the dielectric constant (εr) is 8100, which are all close to or even better than that of the pure undoped BCTS ceramics. The Curie temperature also improved, from 85 °C for pure BCTS to 140 °C for BCTS–0.07 LiF sheets. Furthermore, by using the vibration system and fixing 1.5 g tip mass at the end of the sheets, as the vibration frequency is 20 Hz, the proposed piezoelectric ceramic sheets also reveal a good energy harvesting performance at the maximum output peak voltage of 4.6 V, which is large enough and can be applied in modern low-power electronic products.

On the SiO2/Si(100) substrates, Bi3.9La0.1Ti2.9V0.1O12 (BLTV) ferroelectric thin films were deposited to form a metal-ferroelectric-metal (MFM) structures and improved by the low temperature supercritical carbon dioxide fluid (SCCO2) post-treatment process. The dielectric and ferroelectric characteristics of the as-deposited BLTV thin films were measured and investigated by the XPS, C-V, and J-E measurement. From the measured results, after the SCCO2 post-treatment, the capacitance, leakage current density, coercive field, and remnant polarization of the BLTV thin films were all improved obviously. Finally, the mechanism concerning the dependence of electrical properties of the ferroelectric thin films was also investigated.

Many nonvolatile memory devices such as, ferroelectric random access memory (FeRAM), magnetic random access memory (MRAM), ovonic universal memory (OUM), and resistive random access memory (RRAM) were considerable discussed and investigated. For these nonvolatile memory devices, the RRAM devices will play an important role because of its non-destructive readout, low operation voltage, high operation speed, long retention time, and simple structure. The RRAM devices were only consist of one resistor and one corresponding transistor. In this study, the CuO thin films deposited on ITO/glass and Pt/Ti/SiO2/Si substrates for applications in RRAM devices were produced and investigated. The optimal sputtering conditions of as-deposited CuO thin films were the rf power of 80 W, chamber pressure of 20 mTorr, substrate temperature of 580°C, and an oxygen concentration of 40%. The basic mechanisms for the bistable resistance switching were observed. The electrical and physics properties of CuO thin films for applications in RRAM devices were discussed.

In this study, we investigated the structure and ferroelectric properties of the as-deposited (Bi3.25Nd0.75)(Ti2.9V0.1)O12ferroelectric thin films on ITO substrate fabricated by rf magnetron sputtering method. The electrical, ferroelectric and physical characteristics of as-deposited (Bi3.25Nd0.75)(Ti2.9V0.1)O12thin films were developed under different conditions to find the optimal deposited parameters. The crystalline structure of the prepared (Bi3.25Nd0.75)(Ti2.9V0.1)O12thin films was analyzed by X-ray diffraction (XRD). Field emission scanning electron microscopy (FESEM) was used to observe the film thickness and the surface morphology including grain size and porosity. Additionally, the remnant polarization of the as-deposited ferroelectric thin films was improved by neodymium and vanadium elements doped in this study. The remanent polarization of as-deposited ferroelectric thin films was 11 μC/cm2as the measured frequency of 1kHz. Finally, the polarization of as-deposited ferroelectric thin film capacitor was decreased by 9% after the fatigue test with 109switching cycles.

The subject of this work was to study the photoluminescence characteristics of nanoZnO and SiO2powders into Zn2SiO4phosphor, and to achieve better control on grain size and grain shape than traditional powder. The manganese elements were used to replace Zn2SiO4defects and to achieve better control on grain size and grain shape than traditional powder. With different sintering atmosphere conditions, the effect of the photoluminescence intensity due to sintering temperature and the concentration of activator were be discussed by the X-Ray diffraction, SEM and TEM were utilized in the characterization of phase purity and microstructure of phosphor particles.

Up to now, the various non-volatile memory devices such as, ferroelectric random access memory (FeRAM), magnetron random access memory (MRAM), and resistance random access memory (RRAM) were widely discussed and investigated. For these nonvolatile memory devices, the resistance random access memory (RRAM) devices will play an important role because of its non-destructive readout, low operation voltage, high operation speed, long retention time, and simple structure. The resistance random access memory (RRAM) devices were only consisting of one resistor and one corresponding transistor. The subject of this work was to study the characteristics of manganese oxide (MnO) thin films deposited on transparent conductive thin film using the rf magnetron sputtering method. The optimal sputtering conditions of as-deposited manganese oxide (MnO) thin films were the rf power of 80 W, chamber pressure of 20 mTorr, substrate temperature of 580°C, and an oxygen concentration of 40%. The basic mechanisms for the bistable resistance switching were observed. In which, the non-volatile memory and switching properties of the manganese oxide (MnO) thin film structures were reported and the relationship between the memory windows and electrical properties was investigated.

The shifted band and high intensity of the photoluminescence characteristics for RTA-treated Si+-implanted SiO2thin films for 400-nm-thick thickness using post-CTA processing were discussed and investigated. The samples were treated in the temperature of 1150°C and 20s RTA processing under dry nitrogen atmosphere. The PL band of thin films obtained was 1.7 eV. However, the PL intensity of thin films was continuous decreased for RTA annealing time increased. In this study, the PL band for RTA-treated thin films using 1h post-CTA processing was shifted from 1.5 to 1.67 eV. In addition, the PL intensity of the thin films was increased under the post-CTA annealing time increased to 60s. From the plan-view of the HRTEM image, the Si nanocrystals of the RTA-treated thin films using post-CTA processing were observed. These results were related to the presence and variation of silicon Si nanocrystals embedded in thin films.

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.

Supercritical carbon dioxide (SCCO2) fluid technology was applied to indium-tin-oxide (ITO) electrode to improve the resistive switching characteristic of silicon oxide RRAM through hydride oxidation for the first time. We found device power consumption can be effectively reduced so that side effects can be also restricted under device operation. By applying SCCO2 fluid, more oxygen ions will be introduced into the ITO electrode and thus the participation of net oxygen ions in the RRAM redox reaction will increase. Fourier transform spectroscopy and X-ray photoelectron spectroscopy were used to confirm hydride oxidation on ITO electrode. Combined with the current fitting results, we proposed a reaction model to explain the improvement of resistive switching in RRAM by SCCO2 fluids.

We demonstrated that the supercritical CO2 fluid treatment was a new concept to efficiently reduce the operation current of resistance random access memory. The dangling bonds of tin-doped silicon oxide (Sn:SiOx) thin film were passivated by the hydration–dehydration reaction through supercritical CO2 fluid treatment, which was verified by the XPS and FTIR analyses. The current conduction mechanism of low resistance state in post-treated Sn:SiOx thin film was transferred to hopping conduction from Ohmic conduction. Furthermore, the current conduction mechanism of high resistance state in the memory device was transferred to Schottky emission from Frenkel–Poole conduction. The phenomena were attributed to the discontinuous metal filament formed by hydration–dehydration reaction in Sn:SiOx thin film through supercritical fluid treatment. Finally, a reaction model was proposed to explain the mechanism of current reduction in Sn:SiOx thin film with supercritical CO2 fluid treatment.

The bipolar switching and electrical conduction properties in transparent vanadium oxide (VO) resistance random access memory device were investigated in this study. The as-deposited VO thin films were deposited onto transparent indium tin oxide (ITO) substrate for the possible application in the structure of system on panel (SOP) devices. The transmittance of as-deposited VO thin films within the UV–vis spectrum in the wavelength range of 300–1100 nm was obtained. In addition, the Al/VO/ITO device shows reliable bipolar switching behaviors. The on/off ratio and biopolar switching cycling of two stable states for resistance random access memory device were found. We suggested that the current–voltage characteristics were governed by the space charge limit conduction (SCLC) transport models mechanism in low and high voltage regions.

Using RF magnetron sputtering technique, the (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 and (Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 thin films were successfully deposited and annealed on the Pt/Ti/SiO2/Silicon substrates, and their electrical and physical characteristics had been investigated and presented. The dielectric constant and leakage current density of as-deposited (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 thin films were obtained under optimal sputtering parameters. Additionally, the maximum dielectric constant and leakage current density of annealed BSTZ films under the rapid temperature annealing and conventional furnace annealing would be increased, as the temperature increased to 700°C. Further, the maximum remnant polarization and coercive field of (Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 films were found and calculated from the P-E curves. Finally, for obtaining larger storage capacity and higher density of dynamic random access memory devices in the future, the experimental results indicated the correlation between the electrical characteristics...

We investigated that Al/Ba(Zr0.1Ti0.9)O3 (BZT)/insulator-Silicon metal-ferroelectric-semiconductor (MFIS) and Al/BZT/Pt/Ti/SiO2/Silicon metal-ferroelectric-metal-insu- lator-semiconductor (MFMIS) ferroelectric structures and investigated the memory effect and dielectric constant with different insulator materials of thin films in the MFIS and MFMIS. The BZT thin films on SiO2/Si substrates show good capacitance-voltage characteristics and the threshold voltage shift of 20 V at applied ±30 V bias. However, the leakage current density of BZT on SiO2/Si at 0.5 MV/cm is two orders of magnitude lower than that on SixNy. The clockwise hysteresis loops in C-V curves of the MFIS structure were also observed clearly. From the dependence of C-V properties on different insulator materials, it is deduced that hysteresis loop dominated by the ion vacancy, defect and trap charges in the SixNy films.

To discuss the optoelectronic effect on resistive random access memory (RRAM) devices, the bipolar switching properties and electron-hole pair generation behavior in the transparent indium tin oxide (ITO) electrode of Gd:SiO2 thin films under the ultraviolet (λ = 400 nm) and red-light (λ = 770 nm) illumination for high resistance state (HRS)/low resistance state (LRS) was observed and investigated. In dark environment, the Gd:SiO2 RRAM devices exhibited the ohmic conduction mechanism for LRS, exhibited the Schottky emission conduction and Poole-Frankel conduction mechanism for HRS. For light illumination effect, the operation current of the Gd:SiO2 RRAM devices for HRS/LRS was slightly increased. Finally, the electron-hole pair transport mechanism, switching conduction diagram, and energy band of the RRAM devices will be clearly demonstrated and explained.

To effectively lower the power consumption effect of Sn:SiO2 RRAM devices, the electrical hopping conduction mechanism for set/reset state was effectively used and achieved by different constant compliance current forming process. To assume and discuss the tin metal clustered reaction and electron transport behaviors in metallic filament path-forming model, the various electrical switching current and conduction mechanism model of the Sn:SiO2 RRAM devices for different constant compliance current were also investigated and described. Finally, the switching current relationship between hopping conduction energy and average inter-trap distance properties of the RRAM devices was also simulated and demonstrated in this study.

In this study, the electrical conduction and bipolar switching properties in transparent vanadium oxide thin films are investigated and discussed. (110)-oriented vanadium oxide thin films were well deposited onto transparent ITO substrates for the possible development of applications in the structure of system-on-panel devices. For the as-deposited vanadium oxide thin films, they were prepared for 1 h by a rf magnetron sputtering method of rf power 130 W, chamber pressure 10 mTorr, substrate temperature 550 °C, and different oxygen concentrations. In addition, the Al/V2O5/ITO device presents reliable and bipolar switching behavior. The on/off ratio and switching cycling of two stable states are found and discussed. We suggest that the current–voltage characteristics are governed by ohmic contact and Poole−Frankel emission transport model mechanisms in low- and high-voltage regions, respectively.

The structure and electrical characteristics of the lead-free Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3 (x=0~0.05) piezoelectric ceramics for the conventional solid-state reaction method and the B-side pre-calcined method were achieved and compared. For the B-side pre-calcined method, the lead-free ceramic material exhibited the excellent electrical and piezoelectric properties. The relative dielectric constant (εr) and loss (tan δ) of the Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3 for x=0.03 using the B-side pre-calcined method were 1223 and 0.021, respectively. In addition, the electromechanical coupling factors (kp) and Curie temperature (Tc) was 48.5 % and 315°C. Finally, the electrical properties of the lead-free Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3(x=0~0.05) homogeneity ceramics improved by the B-side pre-calcined method were also investigated and discussed.

Aluminum Oxide microwave dielectric ceramics exhibit good microwave dielectric characteristics and suitable be used in the microwave devices. In this letter, using screen-printing technique and Ag/Pd paste, a novel dual-mode 2.4 GHz microstrip bandpass filter with U-shaped defected ground structure is screen printed on the Aluminum Oxide (Al2O3, relative dielectric constant=9.8) microwave dielectric ceramic substrate. In addition, a pair of input/output microstrip lines are designed to be 50 Ω and coupled to a λ/4×λ/4 square loop resonator. And in the ground plane, a U-shaped defected ground structure is used toλ excite the degenerate modes, which can be considered as a perturbation element to control the odd-mode frequency and -3 dB bandwidth of the bandpass filter. Finally, the coupling effects between these degenerate modes are presented and detailed investigated.

In this study, the effects of La and V doping on Bi4Ti3O12(BLTV) ferroelectric thin films deposited on ITO/glass substrates using rf magnetron sputtering were produced and investigated. The effect of oxygen concentration and RF power on the physical and electrical characteristics of BLTV thin films was determined. The physical characteristics of BLTV thin films were obtained by the XRD pattern, SEM and AFM. The variations of crystallization, surface roughness and thickness of BLTV thin films were discussed. The electrical properties of BLTV thin films deposited under various parameters were measured by the HP4156C.

In this experimental, solid state method is used to synthesize proportioned nano-ZnO and SiO2 powders into Zn2SiO4 phosphor, and to achieve better control on grain size and grain shape than traditional powder. La is used to replace Mn; and to achieve better control on grain size and grain shape than traditional powder. With different sintering conditions, With different sintering conditions, the effect of the luminescent intensity due to sintering temperature and the concentration of activator would be discussed by the X-Ray Diffraction, SEM and TEM were utilized in the characterization of phase purity and microstructure of phosphor particles. Photoluminescence (PL) spectroscopy was utilized to characterize the optical properties. This use of phosphor materials is the application of the main light source, display components. Therefore, our study zinc silicate as the main principle of doping Mn, La of the characteristics of, expects to find the best glow.

We have investigated the structure and ferroelectric properties of the Bi3.25La0.75Ti3O12 (BLT) thin films on SiO2/Si substrate fabricated by sol-gel method. We used the BLT films were annealed at various temperatures of 600, 650, and 700°C for one hour by conventional furnace annealing (CTA). The temperature dependence of leakage currents densities of ferroelectric BLT thin films. The crystalline structure of the prepared BLT thin films was analyzed by X-ray diffraction (XRD). Field emission scanning electron microscopy (FESEM) was used to observe the film thickness and the surface morphology including grain size and porosity. The leakage current density and capacitance of thin film were measured by HP4156C.

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.

In order to improve the piezoelectric and aging properties of the lead-free Li 0.06 (K 0.48 Na 0.52 ) 0.94 (Nb 0.86 Ta 0.08 Sb 0.06 )O 3 piezoelectric ceramics, the conventional solid-state reaction method and the B-side pre-calcined method were achieved and compared in this paper. The physical and electrical properties of the lead-free Li 0.06 (K 0.48 Na 0.52 ) 0.94 (Nb 0.86 Ta 0.08 Sb 0.06 )O 3 piezoelectric ceramics material were investigated and discussed. For the B-side pre-calcined method, the ceramic material exhibited the excellent electrical and piezoelectric parameters. Finally, the electromechanical coupling factors, the resonance frequencies, and the resonance resistances of the lead-free ceramic materials were also discussed.