Thin film standardless analysis used in TEM asbestos EDS analysis

A thin film standardless analysis method, based on the Cliff-Loriner factor k, has been used to do quantitative x-ray analysis of asbestos fibers in the TEM. The results of the analysis of four minerals at 120 keV were close to the theoretical value. The ionization cross section Q has been revised experimentally to improve the analysis of asbestos.The Cliff-Lorimer factor has been used in TEM thin film analysis since 1975. The factor kAB is used in the following equation:CA/CB = kAB IA/IBwhere CA and CB is the weight percent of the elements A and B. The IA and IB are x-ray intensities corresponding to elements A and B. In this paper the calculated k values2 will be used for standardless quantitative analysis.In the thin film, when the effects of the backscattering electron, x-ray absorption, and secondary fluorescence are not considered, the x-ray intensity iswhere pt is the mass depth AA is the atomic weight of element A, W is the fluorescence yield, L is the ratio of the x-ray lines and T is the detector efficiency.

Download Full-text

Characterization of an Organic Field-Effect Thin-Film Transistor in Operation Using Fluorescence-Yield X-Ray Absorption Spectroscopy

Physical Review Letters ◽

10.1103/physrevlett.107.147401 ◽

2011 ◽

Vol 107 (14) ◽

Cited By ~ 8

Author(s):

Hiroyuki S. Kato ◽

Hiroyuki Yamane ◽

Nobuhiro Kosugi ◽

Maki Kawai

Keyword(s):

Thin Film ◽

Absorption Spectroscopy ◽

Field Effect ◽

Thin Film Transistor ◽

Fluorescence Yield ◽

X Ray ◽

X Ray Absorption

Download Full-text

X-ray microanalysis of thin specimens in the transmission electron microscope at voltages up to 1000 Kv.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109847 ◽

1978 ◽

Vol 36 (1) ◽

pp. 540-541

Author(s):

G. Cliff ◽

M.J. Nasir ◽

G.W. Lorimer ◽

N. Ridley

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Weight Fraction ◽

Present Series ◽

Constant Independent ◽

X Ray ◽

Transmission Electron ◽

Series Of Experiments ◽

Image Position ◽

X Ray Absorption

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.

Download Full-text

Gaussian ϕ(ρz) curves: Comparison with other models

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134557 ◽

1990 ◽

Vol 48 (2) ◽

pp. 192-193

Author(s):

Alberto Riveros ◽

Gustavo Castellano

Keyword(s):

Good Description ◽

Bulk Sample ◽

Incident Electron Energy ◽

Power Mean ◽

General Shape ◽

Ionization Cross ◽

X Ray ◽

Mass Absorption ◽

Absorption Correction ◽

Image Position

X ray characteristic intensity Ii , emerging from element i in a bulk sample irradiated with an electron beam may be obtained throughwhere the function ϕi(ρz) is the distribution of ionizations for element i with the mass depth ρz, ψ is the take-off angle and μi the mass absorption coefficient to the radiation of element i.A number of models has been proposed for ϕ(ρz), involving several features concerning the interaction of electrons with matter, e.g. ionization cross section, stopping power, mean ionization potential, electron backscattering, mass absorption coefficients (MAC’s). Several expressions have been developed for these parameters, on which the accuracy of the correction procedures depends.A great number of experimental data and Monte Carlo simulations show that the general shape of ϕ(ρz) curves remains substantially the same when changing the incident electron energy or the sample material. These variables appear in the parameters involved in the expressions for ϕ(ρz). A good description of this function will produce an adequate combined atomic number and absorption correction.

Download Full-text