Direct current hopping conductance in one-dimensional diagonal disordered systems

Based on a tight-binding disordered model describing a single electron band, we establish a direct current （de） electronic hopping transport conductance model of one-dimensional diagonal disordered systems, and also derive a dc conductance formula. By calculating the dc conductivity, the relationships between electric field and conductivity and between temperature and conductivity are analysed, and the role played by the degree of disorder in electronic transport is studied. The results indicate the conductivity of systems decreasing with the increase of the degree of disorder, characteristics of negative differential dependence of resistance on temperature at, low temperatures in diagonal disordered systems, and the conductivity of systems decreasing with the increase of electric field, featuring the non-Ohm＇s law conductivity.

Discharge Characteristics of an Atmospheric Pressure Argon Plasma Jet Generated with Screw Ring-Ring Electrodes in Surface Dielectric Barrier Discharge

An atmospheric-pressure argon plasma jet with screw ring-ring electrodes in surface dielectric barrier discharge is generated by a sinusoidal excitation voltage at 8 kHz. The discharge characteristics, such as rotational and vibrational temperature of nitrogen, electronic excitation temperature, oxygen atomic density, nitrogen molecular density, and average electron density, are estimated. It is found that the rotational temperature of nitrogen is in the range of 352 ～ 392 K by comparing the simulated spectrum with the measured spectrum at the C3Πu → B3Πg （△ν = 2） band transition, the electronic excitation temperature is found to be in the range of 3127 ～ 3230 K by using the Boltzmann plot method, the oxygen atomic and nitrogen molecular density are of the order of magnitude of 1016 cm-3 by the actinometry method, and the average electron density is of the order of magnitude of 1012 cm-3 by the energy balance equation. Besides, the effective power, conduction, and displacement current are measured during the discharge.

Resistive switching characteristics of Ti/ZrO_2/Pt RRAM device

In this paper, the bipolar resistive switching characteristic is reported in Ti/ZrO2/Pt resistive switching memory de- vices. The dominant mechanism of resistive switching is the formation and rupture of the conductive filament composed of oxygen vacancies. The conduction mechanisms for low and high resistance states are dominated by the ohmic conduc- tion and the trap-controlled space charge limited current （SCLC） mechanism, respectively. The effect of a set compliance current on the switching parameters is also studied： the low resistance and reset current are linearly dependent on the set compliance current in the log-log scale coordinate; and the set and reset voltage increase slightly with the increase of the set compliance current. A series circuit model is proposed to explain the effect of the set compliance current on the resistive switching behaviors.

Influence of ozone on the rheological and electrical properties of stored human blood

Blood stored in a blood bank undergoes a series of chemical changes and storage lesions. The purpose of this study was to assess the effect of ozone on the rheological and electrical properties of stored human blood. Venous blood samples, obtained from three healthy humans, were treated with different concentrations of ozone （30, 50, 70 and 80 ~tg/mL） for three weeks in vitro. Ozone was generated from portable medical-grade oxygen using elec- trical corona arc discharge. The ultraviolet-visible absorption of hemoglobin in the wavelength of 300-700 nm showed that ozone in this range did not interact with iron ions and it was not toxic below the concentration of 80 ~tg/mL. The changes of blood viscosity were also measured. The electrical conductivity and permittivity, in the frequency range from 5 to 50 MHz, were measured in the control and treated samples subjected to different concentrations of ozone at different stored periods. The results showed that the conductivity and permittivity measurements may serve as a useful indicator in the quality assessment of blood samples stored in the blood bank.

Current mechanism and band alignment of Al(Pt)/HfGdO/Ge capacitors

HfGdO high-k gate dielectric thin films were deposited on Ge substrates by radio-frequency magnetron sputtering. The current transport properties of Al（Pt）/HfGdO/Ge MOS structures were investigated at room temperature. The results show that the leakage currents are mainly induced by Frenkel-Poole emissions at a low electric field. At a high electric field, Fowler Nordheim tunneling dominates the current. The energy barriers were obtained by analyzing the Fowler Nordheim tunneling characteristics, which are 1.62 eV and 2.77 eV for Al/HfGdO and Pt/HfGdO, respectively. The energy band alignments for metal/HfGdO/Ge capacitors are summarized together with the results of current-voltage and the x-ray photoelectron spectroscopy.