共查询到20条相似文献,搜索用时 15 毫秒
1.
Sabine Dreer Peter Wilhartitz Edgar Mersdorf Gernot Friedbacher 《Mikrochimica acta》1999,130(4):281-288
Thin films of silicon oxynitride with diverse compositions were prepared by de-magnetron sputtering of silicon, utilising oxygen and nitrogen gas flows and the sputtering power to vary the composition. In order to investigate the composition of these films, a method of analysis by electron probe micro analysis with energy dispersive detection was developed and the figures of merit were compared to the wavelength dispersive method used by other authors. The precision and repeatability of the results are evaluated and the accuracy is checked by comparison with Rutherford backscattering and nuclear reaction analysis. Energy dispersive X-ray spectrometry was proven to be applicable to analyse silicon oxynitride films of any composition yielding quantitative results for nitrogen and oxygen as well as silicon. Besides the good analytical performance, electron probe micro analysis with energy dispersive X-ray spectrometry has turned out to be a non-destructive, quick, easy to use and cost effective tool for the routine analysis of light elements in thin films. 相似文献
2.
Stephen J. B. Reed 《Mikrochimica acta》2000,132(2-4):145-151
“Trace” elements may be defined as elements whose concentrations are of a similar order to the detection limit. In WD analysis
the detection limit is a function of the ‘figure of merit’ P2/B, where P is the pure-element peak intensity and B the background intensity. With normal analysis conditions detection limits
of ∼100 ppm are typical, but substantial improvements can be achieved by using higher values of accelerating voltage and beam
current. Long counting times are also advantageous, but should preferably be divided into relatively short alternating peak
and background measurements to minimise the effect of instrumental drift. Using separate routines for trace and major element
analysis is desirable owing to their different requirements. As the statistically defined detection limit is reduced, errors
due to background nonlinearity and interferences (overlaps) from other elemental peaks become more probable. Spectrum simulation
is useful for optimising background offsets and choice of crystal to minimise interferences, and estimating interference corrections
when these are necessary. ‘Blank’ standards containing none of the trace elements of interest are also useful for quantifying
background nonlinearity. 相似文献
3.
Sabine Dreer Peter Wilhartitz Kurt Piplits Herbert Hutter Michael Kopnarski Gernot Friedbacher 《Mikrochimica acta》2000,133(1-4):75-87
Silicon- and aluminium oxynitride films have gained attention because of their interesting properties in various fields of
technology. The specific properties strongly depend on the concentration of oxygen and nitrogen in the films. For the quantitative
analysis of homogeneous silicon- and aluminium oxynitride films, EPMA has been proven a very reliable and precise method of
analysis. In order to characterise films with graded composition or interface effects between the film and the substrate it
is necessary to use sputter depth profiling techniques such as SIMS, hf-SNMS, AES, or hf-GD-OES. Unfortunately, stoichiometric
silicon- and aluminium oxynitride films are insulating and therefore charge compensation has to be applied.
For the quantification it was necessary to prepare calibration samples which have been analysed by different bulk analytical
techniques such as NRA, RBS and EPMA. With these calibration samples, sensitivity factors have been determined and the functional
dependence of the sensitivity factors on the composition has been derived. The advantages and disadvantages of the different
sputtering techniques and the applicability of the obtained sensitivity functions for the quantitative depth profiling of
silicon- and aluminium oxynitride films are discussed. 相似文献
4.
The determination of the concentration of light elements, such as carbon, nitrogen and oxygen, in e.g. atmospheric aerosol
particles is important to study the chemical behaviour of atmospheric pollution. The knowledge of low-Z element concentrations gives us information on the speciation of nutrients (species having nutritional value for plants)
and toxic heavy metals in the particles. The capability of the conventional energy-dispersive EPMA is strongly limited for
the analysis of low-Z elements, mainly because the Be window in the EDX detector hinders the detection of characteristic X-rays of light elements
such as C, N, O and Na. WDS is suitable for analysis of light elements, but the measurement of beam sensitive microparticles
requires the minimisation of the beam current and the measurement time. A semi-quantitative analytical method based on EPMA
using an ultra-thin window EDX detector was developed. It was found that the matrix and geometric effects that are important
for low-energy X-rays can be reliably evaluated by Monte Carlo calculations. Therefore, the quantification part of the method
contains reverse Monte Carlo calculation done by iterative simulations. The method was standardised and tested by measurements
on single particles with known chemical compositions. Beam-sensitive particles such as ammonium-sulphate and ammonium-nitrate
were analysed using a liquid nitrogen cooled sample stage. The shape and size of the particles, which are important for the
simulations, were determined using a high-magnification secondary electron image. Individual marine aerosol particles collected
over the North Sea by a nine-stage Berner cascade impactor were analysed using this new method. Preliminary results on five
samples and 4500 particles show that the method can be used to study the modification of sea-salt particles in the troposphere. 相似文献
5.
In this paper the analysis of a family of rough silicon single crystal surfaces covered with native oxide layers is performed
using a combined optical method based on a multisample treatment of the experimental data obtained using variable angle of
spectroscopic ellipsometry and near normal spectroscopic reflectometry. Within this analysis the values of the thicknesses
of the native oxide layers are determined together with the values of statistical parameters of roughness, i.e. with the rms
values of the heights and the values of the autocorrelation lengths, for all the samples studied. For interpreting experimental
data the perturbation Rayleigh–Rice theory and scalar diffraction theory are employed. By means of the results of the analysis
achieved using both the theories limitations of the validity of these theories is discussed. The correctness of the values
of the statistical parameters determined using the optical method is verified using AFM measurements. 相似文献
6.
Väino Sammelselg Eero Rauhala Kai Arstila Alex Zakharov Jaan Aarik Arvo Kikas Juhan Karlis Aivar Tarre Anni Seppälä Jelena Asari Indrek Martinson 《Mikrochimica acta》2002,139(1-4):165-169
Titanium oxide and zirconium oxide thin films deposited on silicon substrates were characterised using electron probe microanalysis
(EPMA), Rutherford backscattering spectroscopy (RBS), time-of-flight elastic recoil detection analysis (TOF-ERDA) and scanning
photoelectron microscopy (SPEM). The composition and mass thickness of the films were determined and the results of different
methods compared. It was revealed that the synchrotron radiation used for SPEM studies caused considerable modification of
zirconia films grown at low temperatures. 相似文献
7.
Compositional characterization of metal-DLC (metal-containing diamond-like carbon) hard coatings is carried out by (WDS)-EPMA
and MCs+-SIMS. EPMA enables accurate (± 5% relative) quantitative analysis including minor concentrations (0.1–10 at%) of N, O and
Ar. Under conditions of “near-surface” EPMA (E0 < 10 keV) the influence of surface oxide films on “pure” metal standards may be a limiting factor in respect of accuracy.
Depth profiling of sufficiently “thick” layered structures (film thickness ≥ 2 μm) is carried out by EPMA-line scans along
mechanically prepared bevels. The depth resolution is about 0.2 μm. SIMS in the MCs+-mode enables high resolution (< 20 nm) depth profiling of metal-DLC layered structures including the determination of H (1–20 at%).
MCs+-SIMS, i.e. employing Cs+ primary ions and monitoring MCs+ molecular secondary ions (M is the element of interest) is presented as a promising route towards sufficiently accurate (10–20%)
SIMS-quantification. Matrix-independent relative sensitivity factors for MCs+-SIMS are derived from homogeneous coating materials defined by EPMA. EPMA proves to be also useful to detect problems related
to SIMS of Ar in metal-DLC materials. The combination EPMA-SIMS is demonstrated as an effective analytical strategy for quality
control in industrial production and to support the development of metal DLC layered structures with optimum tribological
properties. 相似文献
8.
Norbert Lesch Anke Aretz Markus Pidun Silvia Richter Peter Karduck 《Mikrochimica acta》2000,132(2-4):377-382
A common problem in depth profile measurement is the calibration of the depth scale. The new technique of sputter assisted
electron probe microanalysis offers the possibility of calculating the composition as well as the depth scale solely from
the acquired X-ray intensity data without further information, e.g. sputter rates. To achieve a depth resolution that is smaller
than the depth of information of the electron probe, i.e. 0.1–1 μm, special deconvolution algorithms must be applied to the
acquired data.
To assess the capabilities of this new technique it was applied to a Ti/Al/Ti multilayer on Si under different measurement
conditions. Quantitative depth profiles were obtained by application of a deconvolution algorithm based on maximum entropy
analysis. By comparison of these profiles with AES depth profiles and AFM roughness measurements, it was shown that the limiting
factor to the achievable depth resolution is the occurrence of surface roughening induced by the sputtering process rather
than the relatively large depth of information of the electron probe.
We conclude that for certain applications sputter-assisted EPMA can be regarded as a valid depth profiling technique with
a depth resolution in the nm range. 相似文献
9.
Alessandro Borghi Roberto Cossio Filippo Olmi Raffaella Ruffini Gloria Vaggelli 《Mikrochimica acta》2002,139(1-4):17-25
A comparison between major and trace element concentrations in garnet performed by electron microprobe (EPMA) technique is
reported. Quantitative spot analyses and X-ray maps of major elements (Fe, Mg, Mn, Ca) and the trace element yttrium in garnets
from metamorphic rocks are presented. The selected garnet samples come from meta-pelitic and meta-basic specimens belonging
to the tectonic unit of the Monte Rosa Nappe (Western Alps).
In the metapelites, the quantitative Y distribution maps display a prominent increase at the core, the Y abundance varying
by over two orders of magnitude, from about 80 ppm (rim) to over 2100 ppm (core). The Y profiles show well defined patterns
with sharp features that do not correlate with major element distributions. A roughly comparable pattern can be supposed only
with Mn. The Y distribution suggests that the diffusion of Y through the garnet is very slow compared to the major elements,
thus the Y results are suitable for geothermometric estimates.
In the metabasites, the Y spatial distribution is characterised by an increasing content from the core to the rim, displaying
a zoning pattern opposite to the metapelite garnet. Quantitative EPMA analyses range from 1100 ppm at the rim to values lower
than the detection limit at the core.
Therefore, the Y content in the garnet can be related to several chemical and physical variables such as the bulk rock composition
and the phase assemblage. In particular, in the xenotime-bearing metapelitic system the Y distribution seems to be correlated
with metamorphic peak temperature. 相似文献
10.
Monte Carlo simulation of electron transport in solids is widely used in electron microscopy, spectroscopy and microanalysis.
The reliability of physical models incorporated in a Monte Carlo code is usually checked by comparing with experimental results.
Elastic or inelastic collisions are usually considered as the basic interactions of electrons with atoms. In our Monte Carlo
code the single scattering model is employed for simulation of X-ray emission from thin films of Au on the Si substrate. The
electron beam energy was in the range 10–30 keV, the take-off-angle was 40°. The simulated values of X-ray production were
calculated in our Monte Carlo code using several models of ionisation cross-sections. For the emitted intensities the depths
of inelastic collision and X-ray absorption were taken into account, then the k-ratios were calculated. These data were compared with experimental values of k-ratios calculated from X-ray intensities of Au M and Au L characteristic lines. We followed mainly the dependence of the
k-ratios of the film element on film thickness. The film thickness was in the range 0.05–1 μm. Reasonably good agreement was
found for dependences of X-ray intensity on film thickness in the whole energy range and for both lines, especially for Powell’s
model of the ionisation cross-section. 相似文献
11.
Markus Pidun Norbert Lesch Silvia Richter Peter Karduck Wolfgang Bock Michael Kopnarski Peter Willich 《Mikrochimica acta》2000,132(2-4):429-434
A solar control coating was analysed by different methods of surface analysis with respect to the layer sequence and the
composition and thickness of each sublayer. The methods used for depth profiling were Auger electron spectroscopy, electron
probe microanalysis, secondary neutral mass spectroscopy and secondary ion mass spectroscopy based on MCs+. The structure of the coating was unknown at first. All methods found a system of two metallic Ag layers, embedded between
dielectric SnOX layers. Additionally, thin Ni-Cr layers of 1–2 nm were detected on top of the Ag layers. Thus the detected layer sequence
is SnOX/Ni-Cr/Ag/SnOX/Ni-Cr/Ag/SnOX/glass. The Ni:Cr ratio in the nm-thin layers could be quantified by every method, the Cr fraction corresponding to less than
one monolayer. We compare the capabilities and limitations of each method in routinely investigating this solar control coating.
Importance was attached to an effective investigation. Nevertheless, by combining all methods, measuring artefacts could be
uncovered and a comprehensive characterisation of the system was obtained. 相似文献
12.
Depletion of high field strength elements (HFSE: Nb, Ta, Zr, Hf ) relative to other lithophile trace elements in arc magmas
and variations of Nb/Ta and Zr/Hf ratios in mantle-derived rocks can be addressed through studies of minerals, which concentrate
and fractionate these elements. The presence of rutile, a common accessory Ti-oxide phase in various mantle rocks, has often
been invoked to explain the Nb and Ta depletion in arc lavas because it has the highest HFSE abundances among the known mantle
minerals. In this study, we measure the concentrations of Nb, Ta, Zr and Hf (at > 200 ppm) in rutile of two metasomatized
mantle lherzolites using a Cameca SX-100 electron microprobe and obtain Nb/Ta ratios with an accuracy of about ± 5%. Mass
balance calculations indicate that ≤ 1−5% of Nb and Ta in the rocks reside in major minerals and that the balance is hosted
by accessory Ti-oxides. The Nb/Ta ratios vary significantly in nearby rutile grains in both peridotites (17–33, average 23;
12–37, average 21). Therefore, individual rutile grains may not be representative of the total grain population. However,
Nb/Ta ratios measured in the bulk rock lherzolites by solution ICP-MS (21 ± 0.3) are within the analytical error of the average
Nb/Ta values calculated for 5–7 rutile grains in both samples. These results emphasise that a representative grain selection
must be analysed in order to determine trace elements contents of bulk rocks from data on accessory phases. 相似文献
13.
Raffaella Ruffini Alessandro Borghi Roberto Cossio Filippo Olmi Gloria Vaggelli 《Mikrochimica acta》2002,139(1-4):151-158
Quartz is a common phenocryst in acidic volcanic rocks but rarely contributes to the understanding of the magmatic or eruptive
processes due to its apparent chemical homogeneity. Cathodoluminescence studies indicate that volcanic quartz is strongly
zoned with respect to the trace elements. The determination of this zoning can help to elucidate the crystallisation history
of the magmatic rock. Polished thin sections from rhyolitic and dacitic volcanic rocks were examined by cathodoluminescence
mounted on an optical microscope and analysed by electron probe microanalysis. X-ray mapping of the trace elements incorporated
in the zoned quartz was also performed. The interpretation of the data obtained from these different analytical methods provides
useful information on the chemical zoning of single crystals and therefore on the chemico-physical conditions of the melt
from which the quartz crystallised. Quartz from dacitic rock shows a complex cathodoluminescence oscillatory zoning, consisting
of large red-brown and blue bands concentric to a resorbed core. Quartz from rhyolite shows simpler cathodoluminescence zoning,
consisting of dark to bright blue luminescent bands. The EMPA analyses and the X-ray maps combined with the cathodoluminescence
images suggest a clear correlation between the concentrations of some trace element (mainly Al and Ti, acting as activators
of luminescence) and the cathodoluminescence colours pattern zoning. The incorporation of these trace elements during the
growth of the crystals is linked to small variations in the thermo-chemical properties of the magma such as temperature and
chemical composition. 相似文献
14.
Ioannis Polyzos Georgios Tsigaridas Mihalis Fakis John Parthenios Anastassios Fragos Vassilis Giannetas Peter Persephonis John Mikroyannidis 《Monatshefte für Chemie / Chemical Monthly》2001,132(1):169-175
Summary. Two-photon absorption induced fluorescence microscopy was used as a tool for the examination of the spatial distribution
of a thin dye film. The two-photon absorption induced fluorescence signal is essentially the same as that produced by excitation
with a single photon of equivalent energy. When femtosecond pulses are focused into a sample there is an intrinsic spatial
selectivity of the two-photon emission signal, since it is dependent upon the square of the light intensity. This has tremendous
implications in fluorescence microscopy. Since two-photon absorption is confined in a small region at the focal waist of an
objective lens, photodamage and photobleaching of the sample are significantly reduced. In addition, the two-photon signal
has inherent z-axis spatial resolution, which facilitates the construction of 3-D images. In the present work an application of this technique
to a thin film of a dye is presented. The method can generally be applied to thin films made from photonic polymers.
Received June 23, 2000. Accepted (revised) July 31, 2000 相似文献
15.
Loïc Sorbier Elisabeth Rosenberg Claude Merlet Xavier Llovet 《Mikrochimica acta》2000,132(2-4):189-199
We examine the influence of the sample porosity on the X-ray emission from mesoporous alumina bombarded with kilovolt electrons.
Experimental results show that there is a loss of X-rays (Al Kα and O Kα) from those samples when compared to a fully dense
mono-crystalline alumina (sapphire), which depends on the X-ray line, the measurement time and the embedding medium. Both
geometrical and charging effects may be responsibl e for this signal loss. Monte Carlo simulations of the X-ray intensity
emitted from porous alumina, using different models to describe sample porosity, show that the geometrical effect of porosity
itself cannot account for the X-ray loss. Charge trapping effect and/or its combination with porosity is therefore expected
to be the major cause of the signal loss. 相似文献
16.
János Osán Sándor Kurunczi Szabina Török Anna Worobiec René Van Grieken 《Mikrochimica acta》2002,139(1-4):111-117
The combination of single-particle analysis using thin-window EPMA and a reverse Monte Carlo quantification procedure has
been proven to provide semi-quantitative elemental concentrations, including light elements. The capabilities of the method
are demonstrated through three different environmental applications in Hungary. Lake Balaton is the largest lake in central
Europe. It is suspected that the atmosphere is an important source of environmental deterioration of the Lake, relative to
the pollutant supply by rivers and direct discharges. Thin-window EPMA results of around 25,000 individual particles indicated
that the composition of the aerosol did not show characteristic seasonal variation, it was more correlated to the daily meteorological
circumstances.
A serious heavy metal pollution of the river Tisza occurred on 10 March 2000, from a mine-dumping site in Romania. Sediment
samples were taken from the main riverbed at six sites, on 16 March 2000. In some of the samples, pyrite type particles were
observed in high abundance, revealing their dumping-site origin. Biomass burning for energy production has been increased
recently, mostly in households and for space heating. Fly-ash and bottom-ash samples were collected at a 600 kW heating plant
at Sződliget during standard winter operation. Most particles contained over 65% of unburned organic substance. The concentrations
of major elements were obtained for each individual particle using thin-window EPMA, providing accurate matrix composition
for further μ-XRF investigations of the trace element composition. 相似文献
17.
Jose Garcia Susanne Trampert Walter Lengauer Marcel Bohn Vera Ucakar Ivica Smid Klaus Dreyer 《Mikrochimica acta》2000,133(1-4):223-231
WDS-EPMA and GDOES measurements were applied for the characterization of the in-situ surface modification process of (Ti,
W)C-based hardmetals by in-diffusion of carbon and nitrogen leading to complicated microstructures composed by layers and/or
gradients. The calibration of the analytical techniques was performed with chemically characterized specimens prepared by
diffusional techniques or hot-pressing. In addition, for the GDOES method, certified reference materials (CRMs) have been
used. The work was started from a re-investigation of the W-C and Mo-C systems in order to measure homogeneity regions of
the various phases prepared by use of diffusion couples. Subsequently, the metal and non-metal contents of various sequences
of layers and/or gradients in functional-gradient hardmetals (FGHs) were measured. Both methods were employed as complementary
tools to get information about the element-concentration distribution in FGHs so that a better understanding of the influence
of process parameters for fabrication of special hardmetals is possible. 相似文献
18.
This work concentrates on the setting-up of conditions for the quantitative analysis of the composition profiles of major and minor components of float glass surfaces with an electron probe micro-analyser. Since surfaces are modified for depths of 10–50 m, they have been studied both in polished cross-section and perpendicularly to the electron beam by varying its energy to investigate the near-surface region (0–3m). The results demonstrate that combined use of the two methods supplies complete and continuous information on the quantitative distribution from large depths to the first layers of the float surfaces. The experimental conditions, sample preparation, in-depth and lateral resolutions, precision and accuracy of the methods are also investigated. 相似文献
19.
A new model for the ionization depth distribution function has been proposed. Within the framework of this model full electron flux is considered to be divided into two fluxes propagating in forward and backward directions through a sample. The intensities of these fluxes can be derived on the basis of simple assumptions of electron-solid interactions. The approach can be effectively applied to a system with an arbitrary form of depth concentration profile. The obtained results are in reasonable agreement with Monte Carlo simulations and experimental results. Some mathematical techniques have been presented for quantitative analysis of thin films on substrates and element depth distribution. 相似文献
20.
Several analytical techniques have been used to characterize homogeneous films of tungsten-containing hydrogenated carbon (W-C: H), deposited on Si with a film thickness of 1–1.5 m. Electron probe microanalysis (EPMA) enables one to determine the major components W (3–43 at %) and C, impurities (< 2 at %) of Ar and O, and the mass thickness (300–1800 g/cm2) of the films. The agreement between the results of EPMA and the data (W-content, mass thickness) provided by Rutherford backscattering spectrometry (RBS) is 5–10% relative. Quantitative analysis of hydrogen in W-C:H films (1–16 at %) is carried out by the technique of elastic recoil detection (ERD). A suitable scheme for the determination of H in W-C: H films by SIMS is proposed, based on monitoring the intensity ratio of HCs+/CCs+ secondary ions. 相似文献