μ-Statistically Convergent Function Sequences

In the present paper we are concerned with convergence in -density and -statistical convergence of sequences of functions defined on a subset D of real numbers, where is a finitely additive measure. Particularly, we introduce the concepts of -statistical uniform convergence and -statistical pointwise convergence, and observe that -statistical uniform convergence inherits the basic properties of uniform convergence.     

Electrical characteristics of the hydrogen pre-annealed Au/n-GaAs Schottky barrier diodes as a function of temperature

We investigated the passivation effects of hydrogen gas on the Au/n-GaAs Schottky barrier diodes in a wide temperature range. Reference diodes were prepared by evaporating barrier metal on semiconductor wafers un-annealed in N₂ gas atmosphere. The other diodes were made by evaporating barrier metal on n-GaAs semiconductor substrates annealed in H₂ atmosphere. Then, electrical measurements of all diodes were carried out by using closed-cycle Helium cryostat by steps of 20 K in the temperature range of 80-300 K in dark. The basic diode parameters such as ideality factor and barrier height were consequently extracted from electrical measurements. It was seen that ideality factors increased and barrier heights decreased with the decreasing temperature. The case was attributed to barrier inhomogeneity at the metal/semiconductor interface. Barrier heights of the diodes made from samples annealed in H₂ gas atmosphere were smaller than those of reference diodes at low temperatures. Here, it was ascribed to the fact that hydrogen atoms passivated dangling bonds on semiconductor surface in accordance with former studies.     

Local Approximation Properties of Modified Baskakov Operators

In this paper, we introduce a general modification of the classical Baskakov operators which do not need to preserve the test function x ². Then, we study an approximation theorem, a Voronovskaya theorem, and various local approximation results for our modified Baskakov operators.     

Spectrophotometric studies on the interactions of C.I. Basic Red 9 and C.I. Acid Blue 25 with hexadecyltrimethylammonium bromide in cationic surfactant micelles

Interactions between cationic dye-cationic surfactant and anionic dye-cationic surfactant systems were investigated in aqueous solutions using spectrophotometric method at 288.15, 298.15, 308.15 and 318.15 K. C.I. Basic Red 9 (BR9) and C.I. Acid Blue 25 (AB25) were used as cationic and anionic dyes, respectively, and hexadecyltrimethylammonium bromide (HDTMABr) was selected as cationic surfactant in this study. Although there was an interaction between the AB25 and the HDTMABr molecules, an interaction between the BR9 and HDTMABr did not occur due to the electrostatic repulsion forces. Binding constants and partition coefficients between the micellar and the bulk water phases for the AB25-HDTMABr system were calculated from the changes in absorbance values and the critical micelle concentrations at different temperatures. It was found that the values of binding constant and partition coefficient decreased with increasing temperature. Thermodynamic parameters (ΔG⁰, ΔH⁰ and ΔS⁰) were determined for the binding and partition processes of AB25-HDTMABr system. It was concluded from ΔG⁰ values that the binding of AB25 to HDTMABr occurred spontaneously. In addition, the binding and partition processes were exothermic.     

The barrier-height inhomogeneity in identically prepared Ni/n-type 6H-SiC Schottky diodes

The effective barrier heights and ideality factors of identically fabricated Ni/n-type 6 H-SiC Schottky diodes (23 dots) have been calculated from their experimental forward bias current–voltage (I–V) and reverse bias capacitance–voltage (C–V) characteristics. A statistical study related to the experimental barrier heights (BHs) and ideality factors of the diodes has been made. The effective Schottky barrier heights (SBHs) and ideality factors obtained from the I–V and C–V characteristics have differed from diode to diode. The BHs obtained from the I–V characteristics varied from 0.85 to 1.03 eV, the ideality factors varied from 1.13 to 1.40 and the BHs from C^-2–V characteristics varied from 1.10 to 1.70 eV. The experimental BH and ideality factor distributions obtained from the I–V characteristics are fitted by a Gaussian function, and their mean values are found to be 0.92±0.04 eV and 1.29±0.08 eV, respectively. The lateral homogeneous SBH value of 1.16 eV for the Ni/n-type 6H-SiC diodes has been calculated from a linear extrapolation of the effective barrier heights to n_if=1.03. PACS 79.40.+z; 73.40.Sx; 73.30.+y; 71.20.Nr