1. Surface Science @ Universidad Autónoma de Madrid Roberto Otero On behalf of all the members of the Surface Science Laboratory @ Universidad Autónoma de Madrid

2. Nanosciences & Surface Science Optical devices based on organic thin films Nanomechanical biosensors Molecular electronic devices Functionalized surfaces for implant applications Introduction

3. Organic Optoelectronic Devices Example: Pentacene thin films Intensity (a.u.) 2θ (º) C. D. Dimitrakopoulos & P. L. Malefant, Advanced Materials 14, 99 (2002) Introduction

4. Thin Film Growth Introduction For organic adsorbates : -3D molecular structure (degrees of freedom) -Specificity in intermolecular interactions

5. Ultra-High Vacuum (UHV) How long does it take for an atomically clean single-crystal surface to get dirty? Nº of incident molecules/time × area = At RT, P = 1 Atm, m = 4 uma, about 7.71 × 10 27 molecules per second and square meter hit the surface. For Cu (100) (square lattice with lattice parameter 2.56 Å) this number equals 5 × 10 9 molecules/second and unit cell At P = 10 -10 Torr, only 6 × 10 -4 molecules per second and unit cell hit the surface, i.e. an average of 25 min are necessary to have all the unit cells hit by one molecule Introduction

6. Ultra-High Vacuum (UHV) Introduction

7. Ultra-High Vacuum (UHV) Introduction 20 × 20 nm 2 O/Cu(110) P O = 10 -8 Torr t frame = 20 s

8. Experimental Techniques Introduction Structure: –Real Space (STM) –Reciprocal Space (SXRD, TEAS) Chemistry (XPS) Electronic Structure (UPS, STS) Other properties… magnetism? (SP- STM, SMOKE)

9. Scanning Tunneling Microscopy and Spectroscopy

10. Scanning Tunneling Microscopy (STM) STM

11. Things to do in the lab when you have an STM… STM Atomic structure of solid surfaces with vertical pm resolution Morphology of epitaxial systems Subnanometer- resolution electronic spectroscopy Diffusion of atomic adsorbates Atom-by- atom nanostructure fabrication

12. TIREMISU (TIme REsolved MIcroscopy of SUrfaces) STM José María Gallego Me David Écija Christian Urban Marta Trelka

13. SITTA (Sistema Integral de Túnel y Técnicas de Análisis) STM Fabián Calleja Juan José Hinarejos Amadeo L. Vázquez de Parga

14. STM/STS: Layer-Dependent Roughening Transition F. Calleja, M. C. G. Passeggi, Jr., J. J. Hinarejos, A. L. Vázquez de Parga, and R. Miranda, Phys. Rev. Lett. 97, 186104 (2006) STM

15. Diffraction and the Reciprocal Space

16. Elementary Diffraction Theory Reciprocal space vector Wavelength ≈ Lattice parameter Diffraction

17. X-Rays: SXRD λ ≈ 1 Å, E ≈ 12.3 keV → X Rays Large penetration depth!!! Real SpaceReciprocal Space Diffraction

18. Baby Chambers at Synchrotrons Diffraction Jesús ÁlvarezMaría José Capitán Me Hamburg

19. Adenine Self-Assembly Diffraction

20. Molecule Diffraction from Surfaces Diffraction

21. The Atomic and Molecular Beam Diffraction Apparatus at LASUAM Diffraction Guillaume Laurent Daniel Farías Daniel Barredo Pablo Nieto

22. H 2 Diffraction In-plane and out-of-plane H 2 diffraction spectra from Pt(111) recorded along the two main azimuths: P. Nieto, E. Pijper, D. Barredo, G. Laurent, R.A. Olsen, E.J. Baerends, G.J. Kroes and D. Farías, Science 312, 86 (2006) Diffraction

23. Surface Phonons Diffraction Phonons on Pd(110):

24. Chemical and Electronic Characterization

25. Electrons in Solid Spectroscopy

26. XRPS Cristina Navío Jesús Álvarez María José Capitán Spectroscopy

27. X-Ray and UV Photoelectron Spectroscopy (XPS) Spectroscopy 3000 Å x 3000 Å N 1s Fe 2p Fe 4 N stoichiometry

28. Other Techniques

29. SMOKE (Surface Magneto-Optical Kerr Effect) Dr. Julio Camarero HeNe laser polarizer lens Wollaston prism analyser DSO Field servo-loop-control power supply FREQ FIELD fast photodiodes + – Hall signal lens air gap ferrite /2 plate 1  current sensor Magnetism

30. Spin-Polarized STM SampleTip MsMs MTMT Φ EFEF EFEF High current Amadeo L. Vázquez de Parga Magnetism

31. Sample: Mn/Fe(001) Mn grown at 370 K (<4x10 -10 mbar) STM image after depositing 7 ML 140 x 150 nm 2 V s = - 0.5 V I=0.5 nA 6 7 8 9 9 9 8 8 0.16 nm 0.14 nm Fe(001)-whisker Mn(001) film 6 7 8 9 9 9 8 8 dI/dV curves dI/dV map at +0.2 V STS measured with clean W tip Spin-Polarized STM Magnetism

32. 8 9 10 100 x 100 nm 2 V s = - 0.5V, I=0.5nA 10 11 12 Sample voltage [V] -0.50.00.5 1.0 dI/dV [nA/V] 0.5 1.5 2.5 8 9 10 11 dI/dV map at +0.2 V 8 9 10 11 10 9 STM image With the Fe-coated W tip alternating contrast with a clean W tip there is no contrast Reversed contrast with different Fe-coated W tips due to different tip magnetization 9 12 dI/dV curves STS measured at room temperature with Fe-coated W tip 100 x 100 nm 2 Spin-Polarized STM Magnetism

33. 80 x 80 nm 2 I map at V=0.10 V 6.5 ML of Mn/Fe(001) Topography Measured at room temperature Spin-Polarized STM Magnetism

34. Conclusion A multitechnique approach to address problems related with the growth and characterization of nanostructures