No abstract

No abstract

The Gd 2 O 3 /SiO 2 -stacked oxides prepared by thermal oxidation were implemented at 1000°C for 5-30 min in ambient oxygen. The transmission electron microscopy results indicated that the longer the oxidation time the thicker the oxide layer. Meanwhile the grown layer surface roughness is reduced and the hysteresis of the corresponding metal oxide semiconductor capacitor is decreased. Large shifts of flatband voltages are observed when the stacks' layer ͑Gd 2 O 3 /SiO 2 ͒ electrolyte-insulator-semiconductor structure is immersed in the pH 2, 4, 6, 8, and 10 buffer solutions, respectively. The hydrogen ion sensitivity of this structure is found to be 53.31 mV/pH.

No abstract

This investigation explores how oxidation affects the gadolinium oxide capacitor and the corresponding Gd2O3 hysteresis phenomenon. The current-voltage varied with Gd2O3 thickness and a charged capacitance voltage (C-V) curve with a left shift is also observed in experimental results. The breakdown voltages rise with increasing oxidation time, while the corresponding C-V hysteresis gaps decrease with increasing oxidation time.

The formation and electrical characteristics of thermal gadolinium (Gd) oxide films were investigated. A good uniform interface formed by proper treatment was observed by transmission electron microscopy (TEM) examination. The dielectric constant of the thermal Gd oxide films was approximately 10 from capacitance-voltage measurements. The X-ray diffraction (XRD) pattern of the thermal Gd oxide (Gd 2 O 3 ) films showed that they had a cubic structure. The Gd oxides that were oxidized at higher temperatures exhibited smaller grain boundaries than those oxidized at lower temperatures. The grain boundary size of the Gd oxides significantly affects the leakage property. A good Gd oxide quality can be obtained when the thermal oxidation temperature is above 900 C.

Pulsating white dwarf stars can be used as astrophysical laboratories to constrain the properties of weakly interacting particles. Comparing the cooling rates of these stars with the expected values from theoretical models allows us to search for additional sources of cooling due to the emission of axions, neutralinos, or neutrinos with magnetic dipole moment. In this work, we derive an upper bound to the neutrino magnetic dipole moment (µ ν ) using an estimate of the rate of period change of the pulsating DB white dwarf star PG 1351+489. We employ state-of-the-art evolutionary and pulsational codes which allow us to perform a detailed asteroseismological period fit based on fully DB white dwarf evolutionary sequences. Plasmon neutrino emission is the dominant cooling mechanism for this class of hot pulsating white dwarfs, and so it is the main contributor to the rate of change of period with time (Π) for the DBV class. Thus, the inclusion of an anomalous neutrino emission through a nonvanishing magnetic dipole moment in these sequences notably influences the evolutionary timescales, and also the expected pulsational properties of the DBV stars. By comparing the theoreticalΠ value with the rate of change of period with time of PG 1351+489, we assess the possible existence of additional cooling by neutrinos with magnetic dipole moment. Our models suggest the existence of some additional cooling in this pulsating DB white dwarf, consistent with a non-zero magnetic dipole moment with an upper limit of µ ν 10 −11 µ B . This bound is somewhat less restrictive than, but still compatible with, other limits inferred from the white dwarf luminosity function or from the color-magnitude diagram of the Globular cluster M5. Further improvements of the measurement of the rate of period change of the dominant pulsation mode of PG 1351+489 will be necessary to confirm our bound.

A high dielectric constant capacitor with stacked Gd 2 O 3 /SiO 2 oxide prepared by anodic oxidation in pure water is reported in this study. The transmission electron microscopy results indicate that good uniform interfaces are observed. The relative dielectric constant of the anodic Gd 2 O 3 oxides is determined to have a value of about 12 by capacitance-voltage ͑C-V͒ measurement. High breakdown property and left-shift C-V curves are exhibited. This anodic oxidation Gd 2 O 3 /SiO 2 stacked capacitor, which is used as a pH-sensitive element in the structure of an electrolyte insulator semiconductor ͑EIS͒, is investigated. A large shift of the flatband voltage is obtained when the double-layered ͑Gd 2 O 3 /SiO 2 ͒ EIS structures are immersed in various ͑pH 2, 4, 6, 8, and 10͒ buffer solutions.The tendency to scale down the metal oxide semiconductor ͑MOS͒ gate dielectric has been demonstrated recently by shrinking its physical dimension. However, a number of fundamental problems arose when the thickness of the SiO 2 gate oxide became thinner than 3 nm. Many studies 1-4 pointed out that if the thickness is below the required critical thickness, the tunneling effect and the trapping of the thin dielectric layer causes great leakage and results in poor gate isolation. Thus, the critical thickness of the MOS structure becomes an important issue in the semiconductor industry. Today, resources have been invested to focus on studies 5-10 which aim to improve oxide-layer quality and to search for substitute materials.High-k materials can be considered as an ideal substitute material for producing the gate oxide layer. Generally, high-k gate dielectrics need to be thermally and chemically stable on silicon substrates. In addition, they are also required to have a high dielectric constant, low leakage current, and good interface quality. Among high-k materials, thermal oxide Gd 2 O 3 has been proven 11 to have a high dielectric constant and good breakdown strength properties. However, there is still a lack of available studies on anodic oxide Gd 2 O 3 .Considering its characteristic of self-filling and the advantage of low-cost equipment, the production of anodic Gd 2 O 3 oxide is processed. In this work, the anodic Gd 2 O 3 /SiO 2 stacked capacitor applied as a pH-sensitive electrolyte-insulator-semiconductor ͑EIS͒ device was proposed and tested. A good sensitivity of hydrogen ions of the Gd 2 O 3 /SiO 2 EIS devices was demonstrated. ExperimentalThe sample substrate was a p-type single-crystal, 3-8 ⍀ cm, 4 in. diameter, boron-doped, and consisted of ͑100͒-oriented silicon wafer. A thin SiO 2 film was grown by anodic oxidation to prevent metal silicide formation after standard RCA processes. The back side of the Si wafer was used as the anodic contact for anodic oxidation. Platinum was used as the cathode plate and pure water was used as the electrolyte. The purity of pure water is 18 M⍀ cm. The anodic oxidation was carried out with a constant voltage of 30 V for 20 min under a room-temperature ambient in clean room environ...