Automatic measurement of secondary electron emission characteristics of TaC, TiC and ZrC

Abstract

A method and apparatus for plotting automatically the secondary electron emission yield curves from metals in an ultra-high vacuum environment are described. The yield curves from metals can be plotted in times of only a few seconds before the surfaces become contaminated. In addition, both the variation of the back-scattering coefficient with primary energy and the yield with angle of incidence of primaries may be plotted. Typical curves from Ni, Pt and Ta are presented to indicate the performance of the apparatus. Measurements using the apparatus are reported on the secondary electron emission characteristics of the three carbides TaC, TiC and ZrC as a function of primary energy and angle of incidence. In addition the yield curves are correlated with a theoretical universal yield curve.

The secondary electron emission yield for 24 solid elements excited by primary electrons in the range 250–5000 ev: a theory/experiment comparison

“…There is good agreement between the present data of the cleaned sample and that of Bronshtein and Fraiman (1969). Thomas and Pattinson (1969) have measured higher values of d, peaking at d 5 1.3 at 500 eV. The calculations of Ding et al (2001) using Equation (4) are considerably higher than the measurements.…”

“…The present data and that of Bronshtein and Fraiman (1969) are in reasonable agreement, although their results tend to be higher at both low and high PE energy and also show a small bump at about 2500 eV, again indicative of sample contamination. Thomas and Pattinson (1969) …”

Theory Experiment Comparison of the Electron Backscattering Factor from Solids at Low Electron Energy (250–5,000 eV)

“…There have been a number of previous studies of η at low energy (Bronstein and Fraiman, 1969;Bongeler et al ., 1993;Starỳ, 1999;El Gomati and Assa'd, 1998;Shimizu, 1974;Palluel, 1947;Sternglass, 1954;Reimer and Tolkamp, 1980;Thomas and Pattinson, 1969;Moncrieff and Barker, 1978;Bishop, 1966;Darlington and Cosslett, 1962). Many of the available results have been collected into a single document (Joy, 2006b) and can be viewed as a series of tables on the Internet (Napchan, 2006).…”

Electronic structure and optical properties of TaC from the first principles calculation

“…Mechanical, thermal, electrical and optical properties have been investigated from both theoretical and experimental points of view [13][14][15][16][17]. However, to our knowledge, up to now, there has been no calculation of the optical properties of tantalum carbide that includes the full transition matrix.…”