PREZENTACIJA OPREME Institut za nuklearne nauke “Vinča” Laboratorija za atomsku fiziku

1. PREZENTACIJA OPREME Institut za nuklearne nauke “Vinča” Laboratorija za atomsku fiziku Nataša Bibić

2. Skanirajući elektronski mikroskop Philips SEM 501 Transmisioni elektronski mikroskop Philips EM 400 Van de Graaff akcelerator Proizvodjač je High Voltage Engineering Corp. Cambridge-Massachusetts. Koristi Van de Graaff-ov generator 500kV Jonski implanter Visoko-naponski terminal ide od minimalnog napona 30-50 kV do maksimalnog od 500 kV.

3. Sredstva MNZŽS TEM i SEMDonacija King’ College London Februar 2004.god Oktobar Van de Graaff akcelerator 500kV Jonski implanter Donacija Univerzitet Surrey, UK

4. History: First record of using glass lens for magnification was by an Arabian from what is now known as Iran, Alhazen, in the 10 and 11th century. He contradicted Ptolemy's and Euclid's theory of vision that objects are seen by rays of light emanating from the eyes; according to him the rays originate in the object of vision and not in the eye. Because of his extensive research on vision, he has been considered by many as the father of modern optics.

5. 15th century on - Studies done with glass magnifiers to study objects in detail mostly as a curiosity by non-scientists - Antonie van Leeuwenhoek (linen draper) described three shapes of bacterial cells using his simple, single lens microscope (glass bead in metal holder).

8. 1935 - Max Knoll demonstrates the theory of the scanning electron microscope 1938 - First scanning electron microscope produced by von Ardenne von Ardenne Knoll and Ruska 1986 Nobel Prize winners 1939 - Ruska and von Borries, working for Siemens produce the first commercially available EM

9. Resolution  ½  Resolution is limited to approx. 1/2 the wavelength of illuminating source. The greater the accelerating voltage the shorter the l Therefore, a 50,000 volt (50 kV) electron has a wavelength of 0.0055nm and a 1MeV electron has a wavelength of 0.00123nm!

12. 1 MeV 200 kV 100kV

13. SEM TEM

14. SEM

15. TEM

16. Electron scattering from specimen Resolution depends on spot size Typically a few nanometers Topographic scan range: order of mm X mm X rays: elemental analysis

17. Electron Microscopy is usefully because we can resolve very small things. SEM works with reflected electrons yielding surface information. TEM works with transmitted electrons yielding information inside your sample.

18. Scanning Electron Microscope

22. SEMs are patterned after Reflecting Light Microscopes and yield similar information: Topography The surface features of an object or "how it looks", its texture; detectable features limited to a few nanometers Morphology The shape, size and arrangement of the particles making up the object that are lying on the surface of the sample or have been exposed by grinding or chemical etching; detectable features limited to a few nanometers Composition The elements and compounds the sample is composed of and their relative ratios, in areas ~ 1 micrometer in diameter Crystallographic Information The arrangement of atoms in the specimen and their degree of order; only useful on single-crystal particles >20 micrometers

23. Laboratorija za atomsku fiziku Philips SEM 501

24. Transmission Electron Microscopes:Widely used in materials science and biological researchCapable of magnifying over a extremely wide range (~100 to >1,000,000 x) Excellent spatial resolution (better than 1 nm)Easy to use and very reliable

25. Disadvantages of TEMs: Very expensive to own and operate. Specimen preparation can be time consuming and technically difficult.Specimen is usually chemically fixed and epoxy embedded. Specimen must be sliced into very, very thin sections.*the inside of an electron microscope is a very hostile environment. It is under high vacuum with zero humidity. Also, in the time it takes to make an average 2 sec exposure of your specimen with an 80 KeV beam, the amount of energy the specimen receives is about 5 x109 rads, which is approximately equivalent to the radiation delivered from a 10 megatonHydrogen bomb exploding 30 meters away!

26. TEMs are patterned after Transmission Light Microscopes and will yield similar information. Morphology The size, shape and arrangement of the particles which make up the specimen as well as their relationship to each other on the scale of atomic diameters. Crystallographic Information The arrangement of atoms in the specimen and their degree of order, detection of atomic-scale defects in areas a few nanometers in diameter Compositional Information (if so equipped) The elements and compounds the sample is composed of and their relative ratios, in areas a few nanometers in diameter

27. 100 keV e-l=0.072 angstr. HRTEM sp. res. 0.2 nm

28. A simplified ray diagram of a TEM consists of an electron source, condenser lens with aperture, specimen, objective lens with aperture, projector lens and fluorescent screen.

29. Transmission Electron Microscope Basic premise of a TEM is to project a magnified image of the specimen onto a fluorescent screen where it can be viewed by the operator. The image itself is the result of beam electrons that are scattered by the specimen vs. those that are not.

30. In actuality a modern TEM consists of many more components including a dual condenser system, stigmators, deflector coils, and a combination intermediate and dual projector lens.

31. Total magnification in the TEM is a combination of the magnification from the objective lens times the magnification of the intermediate lens times the magnification of the projector lens. Each of which is capable of approximately 100X. Mob X Mint X Mproj = Total Mag

34. Growth of b-FeSi2 films via noble-gas ion-beam mixing of Fe/Si bilayers

36. Amorphous-iron disilicide: A promising semiconductor

38. TEM IMAGES

39. Laboratorija za atomsku fiziku Philips EM 400

40. Lokacija, Zaduženje Korisnici Laboratorije 040, 020, 030, 050,170 Univerzitet u Novom Sadu Laboratorija 040 N. Bibić M.Popović M.Novaković S. Petrović TEM i SEM Iskorišćenost Period od 1 godine i značajna iskorištenost

41. Potrebe Dodatna oprema za pripremu uzoraka SAMPLE PREPARATION

42. Van de Graaff akcelerator High Voltage Engineering Corp. Cambridge-Massachusetts. Van de Graaff-ov generator 500kV Jonski implanter Visoko-naponski terminal od minimalnog napona 30-50 kV do maksimalnog od 500 kV.

43. In its passage through matter, an ion may interact with • THE ATOMIC ELECTRONS • and/or • THE ATOMIC NUCLEI

46. Principles of ion beam analysis