1. 15/1-08MENA3100 1 st lecture General information, what to learn and some repetition of crystallography

2. 15/1-08MENA3100 Student contact information NameE-mailPhone Jørn Eirik OlsenJorneo(a)student.matnat.uio.no41100739 Jack BonsakJackb(a)ulrik.uio.no97649877 Kai K LangeKaikl(a)student.matnat.uio.no95141689 Joakim AardalJoakimaa(a)student.matnat.uio.no41479008 Magnus KvalbeinMagnuskv(a)student.matnat.uio.no90533341 Einar VøllestadEinarvo(a)student.matnat.uio.no41107628 Halvard HaugHalvarha(a)gmail.com99486757 Kristine KostølKristbko(a)student.matnat.uio.no41634468

3. 15/1-08MENA3100 Who is involved? Anette E. Gunnæs: eleonora(at)fys.uio.no, 91514080 (General, TEM, ED) Johan Taftø: johan.tafto(at)fys.uio.no (waves optics, TEM, EELS) Ole Bjørn Karlsen: obkarlsen(at)fys.uio.no (OM, XRD) Sissel Jørgensen: sissel.jorgensen(at)kjemi.uio.no (SEM, EDS, XPS) Spyros Diplas: spyros.diplas(at)smn.uio.no (XPS) Lasse Vines: Lasse.vines(at)fys.uio.no (SIMS) Terje Finnstad: terje.finnstad(at)fys.uio.no (SPM) Oddvar Dyrlie: oddvar.dyrlie(at)kjemi.uio.no (SPM) Magnus Sørby: magnus.sorby(at)IFE.no (ND) Geir Helgesen: geir.helgesen(at)IFE.no (ND)

4. 15/1-08MENA3100 General information Lectures –Based on “Microstructural characterization of materials” + by Brandon and Kaplan. SPM lecture based on chapter 7.8 in second edition of “Physical methods for materials characterisation” by Flewitt and Wild. EBSD will be based on separate text. –Some parts of the Brandon and Kaplan book will be regarded as self study material and other parts will be taken out of the curriculum (chapter 7 + some sub chapters). Project work –Energy related projects will be announced by the end of January –Two students will work together, rank projects with 1st-3rd priority –Written report, oral presentation and individual examination –Counts 40 % of final grade Laboratories –Three groups: A, B, C –Individual reports –All reports have to be evaluated and found ok before final written exam

5. 15/1-08MENA3100 Laboratory groups ABC Laboratory work will mainly take place on Tuesdays. The trip to IFE, Kjeller has been rescheduled to Wednesday 13th of February!

6. 15/1-08MENA3100 What to learn about Imaging/microscopy –Optical –Electron SEM TEM –Scanning probe AFM STM Diffraction –X-rays –Electrons ED in TEM and EBSD in SEM –Neutrons Spectroscopy –EDS X-rays –EELS Electrons –XPS, AES Electrons (surface) –SIMS Ions Sample preparation –Mechanical grinding/polishing –Chemical polishing/etching –Ion bombardment –Crunching etc…… Mapping of elements or chemical states of elements. The same basic theory for all waves. Different imaging modes.

7. 15/1-08MENA3100 Probes used Visible light –Optical microscopy (OM) X-ray –X-ray diffraction (XD) –X-ray photo electron spectroscopy (XPS) Neutron –Neutron diffraction (ND) Ion –Secondary ion mass spectrometry (SIMS) –Cleaning and thinning samples Electron –Scanning electron microscopy (SEM) –Transmission electron microscopy (TEM) –Electron holography (EH) –Electron diffraction (ED) –Electron energy loss spectroscopy (EELS) –Energy dispersive x-ray spectroscopy (EDS) –Auger electron spectroscopy (AES)

8. 15/1-08MENA3100 Basic principles, electron probe Valence K L M Electron shell Characteristic x-ray emitted or Auger electron ejected after relaxation of inner state. Low energy photons (cathodoluminescence) when relaxation of outer stat. K L M 1s 2 2s 2 2p 2 2p 4 3s 2 3p 2 3p 4 3d 4 3d 6 Auger electron or x-ray Secondary electron Electron

9. 15/1-08MENA3100 Basic principles, x-ray probe K L M Auger electron Photo electron X-ray Valence K L M Electron shell Characteristic x-ray emitted or Auger electron ejected after relaxation of inner state. Low energy photons (cathodoluminescence) when relaxation of outer stat. Secondary x-rays

10. 15/1-08MENA3100 Basic principles Electrons X-rays Ions E<Eo (EELS) BSE SE AE X-rays (EDS) Ions (SIMS) AE PE (XD) X-rays E=Eo (XPS) (Also used for cleaning/thinning samples) SE (SEM) (TEM and ED) You will learn about: - the equipment -imaging -diffraction -the probability for different events to happen -energy related effects -element related effects -etc., etc., etc……..

11. 15/1-08MENA3100 Basic aspects of crystallography Crystallography describes and characterise the structure of crystals The unit cell ! a c b α β γ - Defined by three non planar lattice vectors: a, b and c -The unit cell can also be described by the length of the vectors a,b and c and the angles between them (alpha, beta, gamma). Elementary unit of volume!

12. 15/1-08MENA3100 Unit cell The crystal structure is described by specifying a repeating element and its translational periodicity –The repeating element (usually consisting of many atoms) is replaced by a lattice point and all lattice points have the same atomic environments. –The whole lattice can be described by repeating a unit cell in all three dimensions. The unit cells are the smallest building blocks. –A primitive unit cell has only one lattice point in the unit cell. a c b α β γ Replaces repeating element (molecule, base etc.)

13. 15/1-08MENA3100 Axial systems The point lattices can be described by 7 axial systems (coordinate systems) x y z a b c α γ β Axial systemAxesAngles Triclinica≠b≠cα≠β≠γ≠90 o Monoclinica≠b≠cα=γ=90 o ≠ β Orthorombica≠b≠cα= β=γ=90 o Tetragonala=b≠cα= β=γ=90 o Cubica=b=cα= β=γ=90 o Hexagonala1=a2=a3≠cα= β=90 o γ=120 o Rhombohedrala=b=cα= β=γ ≠ 90 o

14. 15/1-08MENA3100 Bravais lattice The point lattices can be described by 14 different Bravais lattices Hermann and Mauguin symboler: P (primitiv) F (face centred) I (body centred) A, B, C (bace or end centred) R (rhombohedral)

15. 15/1-08MENA3100 Hexagonal unit cell a1a1 a2a2 a3a3 a 1 =a 2 =a 3 γ = 120 o (hkil) h + k + i = 0

16. 15/1-08MENA3100 Space groups Crystals can be classified according to 230 space groups. Details about crystal description can be found in International Tables for Crystallography. –Criteria for filling Bravais point lattice with atoms. –Both paper books and online Figur: M.A. White: Properties of Materials A space group can be referred to by a number or the space group symbol (ex. Fm-3m is nr. 225) Structural data for known crystalline phases are available in books like “Pearson’s handbook of crystallographic data….” but also electronically in databases like “Find it”. Pearson symbol like cF4 indicate the axial system (cubic), centering of the lattice (face) and number of atoms in the unit cell of a phase (like Cu).

17. 15/1-08MENA3100 Lattice planes Miller indexing system –Crystals are described in the axial system of their unit cell –Miller indices (hkl) of a plane is found from the interception of the plane with the unit cell axis (a/h, b/k, c/l). –The reciprocal of the interceptions are rationalized if necessary to avoid fraction numbers of (h k l) and 1/∞ = 0 –Planes are often described by their normal –(hkl) one single set of parallel planes –{hkl} equivalent planes Z Y X (010) (001) (100) Z Y X (110) (111) Z Y X y z x c/l 0 a/h b/k

18. 15/1-08MENA3100 Directions The indices of directions (u, v and w) can be found from the components of the vector in the axial system a, b, c. The indices are scaled so that all are integers and as small as possible Notation –[uvw] one single direction or zone axis – geometrical equivalent directions [hkl] is normal to the (hkl) plane in cubic axial systems uaua a b x z c y vbvb wcwc [uvw] Zone axis [uvw] (hkl) uh+vk+wl= 0

19. 15/1-08MENA3100 Stereographic projection Plots planes and directions in a 2D map Fig 6.5 of Klein (2002) Manual of Mineral Science, John Wiley and Sons All poles in a zone are on the same great circle!!

20. 15/1-08MENA3100 Wulff net Fig 6.8 of Klein (2002) Manual of Mineral Science, John Wiley and Sons

21. 15/1-08MENA3100 Reciprocal vectors, planar distances The reciprocal lattice is defined by the vectors : Planar distance (d-value) between planes {hkl} in a cubic crystal with lattice parameter a: –The normal of a plane is given by the vector: –Planar distance between the planes {hkl} is given by: