Effects of surface treatments on photoelectric work function of silver–nickel alloys

Akbi, Mohamed; Bouchou, Aïssa; Ferhat-Taleb, Mahdjoub

doi:10.1016/j.vacuum.2013.09.003

Cited by 9 publications

(7 citation statements)

References 32 publications

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“…The work function of the NiCr is not reported in the literature since work functions of alloys depend on more facts than just the type of material involved. Surface compositions, micro‐ and even nanostructure and processing parameters of the material have an impact and makes it difficult to give an overall valid value of work function on certain alloys. Due to the measurement results it is expected to be lower for the NiCr probe than for the pure metals.…”

Section: Resultsmentioning

confidence: 99%

Suitability of Various Materials for Probes in Scanning Kelvin Probe Measurements

Huber

Wicinski

Hassel

2017

Physica Status Solidi (a)

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Volta potential of a material can be easily determined by using scanning Kelvin probe (SKP), but up to now there is no standard method established. This study focuses on finding an alternative or even a standard material for SKP probes. Re, Ni, and Mo are analyzed regarding their suitability for serving as tips in SKP measurements. For comparison purposes, a commonly used NiCr probe is analyzed too. Linearity, the sensitivity to humidity changes as well as the lateral and Volta potential resolution are determined for various probe materials. Linearity is excellent for all tested probes. SKP measurements carried out under humidity variations shows dissimilar results for all different metal probes. Lateral and Volta potential resolution are the best for Re and Ni tips. There may be a correlation between the work function of a material and its suitability for serving as a probe in Kelvin measurements − the higher the work function, the better the resolution of Volta potentials. Based on the results, it can be concluded that pure Re and Ni are more suitable for serving as SKP probes than NiCr alloy.

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Section: Resultsmentioning

confidence: 99%

Suitability of Various Materials for Probes in Scanning Kelvin Probe Measurements

Huber

Wicinski

Hassel

2017

Physica Status Solidi (a)

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“…To bring our measurements to a successful conclusion, an adapted experimental apparatus has been built up; it has been briefly given in [14]- [19]. The experimental device is mainly composed of the following elements that are shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…As shown in Fig. 3, the cathode (C) was out of the line-of-sight preventing temperature measurement by contactless methods, such as IR thermometer and pyrometer [14]. Thus, the temperature of the cathode and heating element was measured using two chromel-alumel thermocouples (Thermocoax) [(8), Fig.…”

Section: B Description Of Uv Source Radiationmentioning

confidence: 99%

“…This metallographic polishing type is used to flatten or to remove the protrusions present on the electrodes, by tearing most of the impurities and other surface defects. Each electrode is then subjected to a cleaning in ultrasonic tank (#15 min), in a bath of trichloroethylene, rinsed with water, and then cleaned with a lint free paper soaked in acetone [14]- [19]. This kind of conditioning allows surface cleaning and impurity elimination (adsorbed molecules and atoms).…”

Section: E Preparation and Analysis Of Contactsmentioning

confidence: 99%

“…Table I shows the results obtained at 300, 500, and 800 K for particular values of the photoelectric current I and the wavelength λ. The procedures of cathode heating and temperature measurements have been given in much details in [14], where Fowler's photoelectric method was used for the determination of EWF. However, as above-mentioned, instead of using Fowler isothermal curves, it is common practice to determine the EWF of metals by means of a plot of √ I versus hν, where I is the photocurrent emitted per photon absorbed and hν is the photon energy [13].…”

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A Method for Measuring the Photoelectric Work Function of Contact Materials Versus Temperature

Akbi¹

2014

IEEE Trans. Compon., Packag. Manufact. Technol.

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The nature of the contact material plays a key role to determine the characteristics of electrical arcs and particularly those related to electronic emission. Mechanical and thermodynamic properties as well as electronic emission of such complicated alloys present a lack of reliable and accurate experimental data. The purpose of this paper is to present the development of a method for measuring photoelectric work functions of contact materials. Also reported in this paper are the results of experimental work whose purpose has been the buildup of a reliable photoelectric system and associated monochromatic ultraviolet radiations source, and the photoelectric measurement of the EWF of contact materials. As a first test of the experimental Ultra High Vacuum setup, the electron work functions (EWF) of silver contacts, namely pure polycrystalline metals that are actually used in relays, were measured photoelectrically, using both Fowler's method of isothermal curves and linearized Fowler plots. Ultrahigh vacuum techniques were employed to obtain residual gas pressure of about 5×10 −9 mbar that allows accurate and reliable photoelectric work function measurements. The EWF measured at room temperature of polycrystalline Ag contact (as commercially available) increased from 3.70 eV before heating, to 4.30 eV, and finally, stabilized at the vicinity of 4.26 eV after several vacuum heat treatments at 533 and 773 K. The EWF value obtained, i.e., 4.26 ± 0.03 eV, is in good agreement with the results found in the literature. This shows that the experimental method is valid and the experimental setup is usable. Furthermore, new photoelectric measurements versus temperature have shown a linear decrease of the EWF of silver contacts with increasing temperature, i.e., the temperature coefficient α = dφ/d t is constant and negative α = −4.58 · 10 −4 eV/K in the experiment temperature range 300-780 K.Index Terms-Contact materials, electron work function (EWF), Fowler's Methods, photoemission, temperature dependence, vacuum heat treatment.

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Effects of vacuum heat treatment on the photoelectric work function and surface morphology of multilayered silver–metal electrical contacts

Akbi

Bouchou

Zouache

2014

Applied Surface Science

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Effects of surface treatments on photoelectric work function of silver–nickel alloys

Cited by 9 publications

References 32 publications

Suitability of Various Materials for Probes in Scanning Kelvin Probe Measurements

Suitability of Various Materials for Probes in Scanning Kelvin Probe Measurements

A Method for Measuring the Photoelectric Work Function of Contact Materials Versus Temperature

Effects of vacuum heat treatment on the photoelectric work function and surface morphology of multilayered silver–metal electrical contacts

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