scholarly journals Работа выхода электрона углеродных нанокомпозитных пленок по данным вакуумной и атмосферной фотоэмиссии

2020 ◽  
Vol 90 (6) ◽  
pp. 982
Author(s):  
Д.А. Бокизода ◽  
А.Ф. Зацепин ◽  
Е.А. Бунтов ◽  
А.И. Слесарев
Keyword(s):  
Fermi Level ◽  
Work Function ◽  
Ambient Pressure ◽  
Contact Potential Difference ◽  
Electron Work Function ◽  
Silicon Substrates ◽  
Contact Potential ◽  
Carbon Coatings ◽  
Energy Characteristics

The energy characteristics of carbyne-containing films on copper and silicon substrates have been studied using the methods of optically stimulated electron emission (OSEE) and ambient pressure photoemission spectroscopy (APS). The average contact potential difference and the work function were determined, and the positions of the Fermi level for carbonaceous films of various thicknesses were calculated. It was found that the electron work function and the position of the Fermi level of the studied film samples are independent of the film thickness and the type of substrate. The information capabilities of the OSEE and APS methods for assessing the quality of carbon coatings on various substrates are shown.

scholarly journals Contact potential difference of alloy steel after heat treatment

2020 ◽  
Vol 20 (3) ◽  
pp. 289-294
Author(s):  
L. P. Aref`eva ◽  
A. G. Sukiyazov ◽  
Yu. V. Dolgachev ◽  
L. S. Shakhova
Keyword(s):  
Heat Treatment ◽  
Work Function ◽  
Alloy Steel ◽  
Contact Potential Difference ◽  
Electron Work Function ◽  
Potential Difference ◽  
Polished Surface ◽  
Contact Potential ◽  
Tempering Temperature ◽  
Non Destructive

Introduction. The paper considers an actual issue of the development and application of a non-destructive method for controlling the quality of surfaces of steel products (Kelvin probe method). The work objective is to establish the magnitude of the contact potential difference (CPD) of steel 107WCR5 after heat treatment.Materials and Methods. The object of study is alloy tool steel 107WCR5. The chemical composition of the samples was refined through the optical emission analysis method. To carry out the statistical processing, there were three samples in three series. We chose different heat treatment modes for each series, i.e., quenching with low tempering, strengthening and normalization. The end surfaces of the samples were polished and then one of them was treated with a solution of nitric acid. Further, the measurement of the contact potential difference and statistical data processing were carried out. Results. The data obtained show that the CPD value of steel 107WCR5 samples changes after heat treatment. With an increase in tempering temperature, the contact potential difference of the polished surface and the hardness, decrease almost linearly. Exposure to acid causes a significant decrease and equalization of the contact potential difference for all structures. The contact potential difference of steels 107WCR5 and CT105 is compared. Alloying steel by the elements with the work function values of the electron higher than that of iron causes a decrease in the CPD between the standard and the sample. The CPD behavior under a change in the composition of the steel depends strongly on the presence of alloying elements. The dependence of CPD on the dispersion of the structure is seen in both cases; however, it is more pronounced for 107WCR5 steel. The electron work function of the martensite, troostite, and sorbitol structures obtained as a result of heat treatment of steels 107WCR5 and CT105 is calculated. Discussion and Conclusions. The dependence of the contact potential difference on the structure, chemical and phase composition was experimentally established; the electron work function of steels 107WCR5 and CT105 was calculated. This technique is more sensitive to alloy steel samples than to carbon steel. It seems possible to conclude that the measurement of the contact potential difference can be used to control surfaces exposed to active media or elevated temperatures as a non-destructive express diagnostic method.

An Optical Approach to Evaluating the Effects of Chlorine on the Quality Of Si/SiO2 Interfaces

1996 ◽  
Vol 428 ◽  
Author(s):  
Julia Sherry ◽  
John Lowell ◽  
Tim Hossain ◽  
Damon Debusk
Keyword(s):  
Alkali Metals ◽  
Contact Potential Difference ◽  
Environmental Concerns ◽  
Device Performance ◽  
Optical Surface ◽  
Contact Potential ◽  
High Injection ◽  
Injection Frequency ◽  
P Type

AbstractIn CMOS, the addition of chlorine particularly in TCA form to the growth of thermal oxides in logic technologies is well-known and pervasive. In addition to the increasing environmental concerns of chlorine use, one of the important parameters is the amount of metallic contamination due to transition metals such as Fe in the Si, and alkali metals like Na in the oxide since these phenomena effect both device performance and quality. However, the ability to measure this parameter on product material is not generally available due to inherent problems with most known methods. In this paper we report on the application of high-injection, frequency based optical surface photovoltage (SPV) and a more recent technique known as a contact potential difference (CPD) to both quantify and qualify as-grown oxides on CZ P-type silicon.

scholarly journals Electron work function in individual multi-walled carbon nanotubes doped with nitrogen and boron

2020 ◽  
pp. 87-92
Author(s):  
N. A. Davletkildeev ◽  
◽  
D. V. Sokolov ◽  
E. Yu. Mosur ◽  
I. A. Lobov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrostatic Force ◽  
Contact Potential Difference ◽  
Electron Work Function ◽  
Chemical Vapor ◽  
Potential Difference ◽  
Contact Potential ◽  
Force Microscopy ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled undoped and doped with nitrogen and boron carbon nanotubes have been synthesized by chemical vapor deposition. Based on the analysis of images obtained by electrostatic force microscopy at various tip voltage, the value of the external contact potential difference between the tip and individual carbon nanotubes is determined. Using the obtained value of the contact potential difference, the electron work functions for undoped and doped with nitrogen and boron individual carbon nanotubes are calculated, which amounted to 4,7; 4,6 end 5,75 eV, respectively

scholarly journals High-entropy ZrTiCrNiCu coating

2021 ◽  
Vol 2064 (1) ◽  
pp. 012080
Author(s):  
V M Yurov ◽  
S A Guchenko ◽  
V I Goncharenko ◽  
V S Oleshko
Keyword(s):  
Surface Energy ◽  
Mechanical Alloying ◽  
Work Function ◽  
Coefficient Of Friction ◽  
Energy Savings ◽  
Contact Potential Difference ◽  
Vacuum Furnace ◽  
Contact Potential ◽  
High Entropy ◽  
First Time

Abstract A magnetron target made of a high-entropy ZrTiCrNiCu alloy was synthesized by mechanical alloying methods followed by annealing in a vacuum furnace. Using this target, coatings were applied to steel samples with a thickness of 7-10 microns. After thermal annealing, the coatings were nanostructured. In terms of microhardness, the ZrTiCrNiCu coating is not inferior to, and in most cases exceeds the hardness of high-entropy equiatomic alloys. A high entropy coating has a low coefficient of friction. They turn out to be anti-friction, which, most likely, leads to energy savings. In this work, the surface energy, contact potential difference and work function of electrons for high-entropy coatings were determined for the first time.

Contact Potential Difference as a Non-Destructive Testing of Steel

2021 ◽  
Vol 316 ◽  
pp. 258-263
Author(s):  
L.P. Aref'eva ◽  
A.G. Sukijazov ◽  
Yu.V. Dolgachev
Keyword(s):  
Chemical Composition ◽  
Contact Potential Difference ◽  
Electron Work Function ◽  
Sharp Decrease ◽  
Sample Surface ◽  
Probe Method ◽  
Potential Difference ◽  
Kelvin Probe ◽  
Contact Potential ◽  
Kelvin Probe Method

For steels of different grades, the effect of the chemical composition, structure, and surface etching on the contact potential difference is studied using the Kelvin probe method. It was shown experimentally that, with a change in the structure and chemical composition, the contact potential difference changes. Etching the surface of the steel with a 4% solution of nitric acid leads to a sharp decrease in the magnitude of the contact potential difference, which allows us to conclude that the value of the electron work function from the sample surface increases. The ability to control the composition and structure of the material by the Kelvin probe method is shown.

Surface Characterization with an Ionization Probe

2010 ◽  
Vol 447-448 ◽  
pp. 518-523
Author(s):  
Chris Yang ◽  
Anatoly Zharin ◽  
Steven Danyluk
Keyword(s):  
Work Function ◽  
Surface Characterization ◽  
Contact Potential Difference ◽  
Ionic Current ◽  
Contact Potential ◽  
Source Power ◽  
Probe Size ◽  
Work Function Difference ◽  
Ionization Probe ◽  
Function Difference

This paper discusses the application of an ionizing source coupled with galvanic differences between metals in a measure of the work function difference between the metal surfaces. The electrical field generated from the contact potential difference (CPD) between two electrodes will cause the gaseous ions to discharge at both surfaces, creating a measurable current. The current depends on the surface size, spacing, and ionizing source power. One of the surfaces (probe) can vary in shape and size, and if inert, can be used to obtain the work function or surface potential of the second surface. The ionic current is proportional to ion mobility, ion generation rate, CPD, and the probe size, but inversely proportional to the spacing between the probe and the sample. It is found, as expected, that there is an approximate linear relationship between the ionization probe signal and the work function of the surfaces of metals.

scholarly journals Studies in contact potentials the condensation of potassium and sodium on tungsten

1937 ◽  
Vol 162 (908) ◽  
pp. 1-31 ◽  
Keyword(s):  
Work Function ◽  
Satisfactory Agreement ◽  
Chemical Reactivity ◽  
Contact Potential Difference ◽  
Ultra Violet ◽  
Potential Method ◽  
Accommodation Coefficient ◽  
Contact Potential ◽  
Adsorbed Complex ◽  
Photoelectric Measurements

Recent work on the adsorption of gases has emphasized both the importance and the difficulty of ensuring the cleanliness of metal surfaces. Methods which involve the "flashing" of a filament of the metal thus present several advantages over the more usual experimental arrangements. With such a filament several physical methods may be employed for investigating the effects of adsorbed films thereon, and a study of the accommodation coefficient (J. K. Roberts 1935) has already yielded much new information. Of the three electrical methods of examination of the film-covered surface, the thermionic work function, the photoelectric work function, and the contact potential, the last is to be preferred, for many films are mobile even at low temperatures, thus precluding use of the thermionic method. In others the photoelectric threshold is so far in the ultra-violet as to render its measurement difficult. From the contact potential the dipole moment of the chemi-adsorbed complex may be obtained. Its value and any variation with the packing density of the film-forming material are required both as a basis for evaluating the true form of the adsorption isotherm as well as for obtaining further insight into the mechanism of chemical reactivity at such surfaces. The measurement of contact potentials by studying the infra-saturation currents in a thermionic tube originated in the work of Richardson and Robertson (1922). Oatley (1936) (cf. also Mönch 1928, 1930) obtained values for the contact potential difference of molybdenum, zinc and platinum against tungsten in quite satisfactory agreement with the best thermionic determinations of the work function; but, in general, the results obtained by contact-potential measurements are not always in satisfactory agreement with thermionic and photoelectric measurements, particularly when dealing with films. Although part of the discrepancy may be due, as Compton and Langmuir (1930) have pointed out, to the fact that in in-homogeneous surfaces the contact-potential method measures the mean work function of the surface, while the other two methods measure the minimum work function, it would be well to survey the experimental technique to choose a procedure which will avoid the more usual difficulties.

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