LABORATORY OF ANALITICAL ELECTRON MICROSCOPY (L-2)
Authorisation:
Accredited activity is defined in the Scope of Accreditation No. AB 120
Address:
Aleksander Krupkowski Institute
of Metallurgy and Materials Science,
Polish Academy of Sciences,
25, Reymonta Str., 30-59 Kraków,
phone: (48)(12) 295 28 00,
fax: (48)(12) 295 28 04,
Head of Laboratory:
Associate Prof. Jerzy Morgiel, PhD, DSc, Eng. ( Adres poczty elektronicznej jest chroniony przed robotami spamującymi. W przeglądarce musi być włączona obsługa JavaScript, żeby go zobaczyć. )
Experts:
Lidia Lityńska, PhD (Deputy Head of Laboratory)
Magdalena Bieda-Niemiec, PhD.
Tomasz Czeppe, PhD
Wojciech Maziarz, PhD, Eng.
Łukasz Major, PhD, Eng.
Justyna Grzonka Msc. Eng.
Władysław Baliga, Eng.
Equipment of laboratory
1. Transmission Electron Microscope PHILIPS CM20 (200kV) TWIN
Technical parameters of PHILIPS CM20 TWIN in IMMS-PAS in Cracow | |
| accelerating voltage | 200 kV |
| point resolution | 0.27 nm |
| line resolution | 0.14 nm |
| min. sample diameter | 2 nm |
| min. magnification | 1 500 |
| max. magnification | 820 000 |
| max. tilt of thin foil | 600 |
Description of the transmission electron microscope:
The transmission electron microscope PHILIPS CM20 (200 kV) TWIN with the EDAX Phoenix attachment for local chemical microanalysis is intended for microstructure observations, phase analysis and local chemical analysis in metals, alloys, semiconductors, ceramic materials and composites.
The operation of the transmission electron microscope is similar to that of the optical microscope used for observation of thin sections of biological materials. The function of the light source is taken over by a 200 kV electron gun, while that of glass lenses is taken over by magnetic ones. The positioning of the sample is also different in both kinds of microscopes. In the optical instrument, it is placed directly in front of the objective lens, ,whereas in the electron microscope, the specimen is immersed within its magnetic field . The other lenses are analogous in both types if instruments.
Schemes of optical (LM) and transmission electron (TEM) microscopes
Electron diffraction, one of the main factors that are decisive for the contrast of images obtained in transmission electron microscope, may also provide valuable information on local phase composition, as it gives an image of elementary unit cell as well as lattice symmetry of analysed crystallite.
Substitution of a beam of light with electrons, which may interact with sample material and produce atom excitation and emission of characteristic X-ray radiation, makes it possible to determine the chemical composition of analysed (local) areas.
2. Transmission Electron Microscope Tecnai G2 F20 (200kV) is equipped with
- field emission gun (FEG)
- two cameras CCD – high resolution Gatan UltraScan and wide angle SIS Megaview as well as detector HAADF intended for scanning-transmission technique STEM
- X-ray spectrometer for the analysis of chemical composition EDAX.
The microscope is adapted to the future application of spectrometry EELS and GIF
Apart from these, the laboratory is equipped with a system of preparing thin foils using Ga+ ion beam, FIB Dual Beam by FEI with an ion gun based on scanning microscope.
Procedures covered by the certification:
1. Microstructure observation in Bright and Dark Field (P/19/IB-05 edition 03 of 25.07.2003)
The aim of the observations is to determine characteristic parameters like dislocation density, grain and subgrain size, distribution and density of precipitates and the like. Observations by means of the dark field technique are suitable to determine the type of analysed precipitate and characterize the ordering, i.e. size and shape, of anti-phase domains. Magnification calibration is performed every 6 months, which guarantees 1 % accuracy.
2. Electron Diffraction (P/19/IB-06 edition 03 of 25.07.2003 edition 03 of 25.07.2003)
The aim of this procedure is to identify phases through the analysis of electron diffraction in parallel illumination (Selected Area Diffraction technique).
It is also possible to obtain information on local orientation of an analysed microstructure and on the relationships between a precipitate and the matrix.
The calibration of camera constant is performed every 6 months, which guarantees 0.01 nm accuracy of the procedures determining a lattice spacing and unit cell.
3. Determination of Local Chemical Composition (P/19/IB-07 edition 03 of 25.07.2003)
The aim of this procedure is to determine local chemical composition with high spatial resolution. It covers thin areas (10 – 100 nm) with the diameter within the range 100 to 10 nm.
This analysis is performed by means of EDS attachment of EDAX Phoenix with (Si;Li) drifted detector with UTW window sensitive to all elements down to Boron. Chemical composition of a sample may be determined either qualitatively (all elements) or quantitatively (for elements of Z>5).
EDS system calibration is performed every 6 months, which guarantees 0.5 – 0.1 % detection limit and relative accuracy of 5 – 2 % of composition, depending on the character of spectral lines of elements found in the analyzed material.
Sample preparations
Samples for TEM observations should be prepared as discs 3 mm in diameter and 0.1 mm thick.
Persons interested in this type of investigation should contact:
Jerzy Morgiel PhD DSc
phone: (0-12) 295 28 53
e-mail: Adres poczty elektronicznej jest chroniony przed robotami spamującymi. W przeglądarce musi być włączona obsługa JavaScript, żeby go zobaczyć.
Application of transmission electron microscope with EDS attachment in investigations of new high strength AlCuMgAg alloys
A map of chemical composition with plate-like precipitates of S and W phase (with the point of analysis indicated), and its corresponding microstructure (the place, in which electron diffraction was taken is indicated)
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