Física dos Materiais FMT0502

Transcrição

1 Física dos Materiais FMT0502 1º Semestre de 2010 Instituto de Física Universidade de São Paulo Professor: Antonio Dominguesdos Santos Fone: de maio

2 Caracterização dos Materiais Microscopy Homepage > Surface Analysis > Surface Science Capabilities Microstructural and Nanoscale Surface Analysis Intertek Surface Analysis laboratories offer a wide range of analytical techniques, expertise and instrumentation. Surface analysis expertise is located on a global basis, and samples are easy to transport to the best Intertek laboratory for your project. Contact Intertek for more information. Intertek Surface science capabiltiies include:: Optical Light Microscopy: Optical light microscopes employ the visible or near-visible portion of the electromagnetic spectrum. Applications include use in the life sciences, metallurgy and electronic industries. SEM Scanning Electron Microscopy: The Scanning Electron Microscope (SEM) analyses the surface of solid objects, producing images of higher resolution than optical microscopy. SEM produces representations of three-dimensional samples from a diverse range of materials. Techniques include cathode-luminescence and backscattering for surface, contrast and elemental analysis. SEM Energy Dispersive X-ray Analysis: SEM/EXDA analysis of small particles by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) is possible without destruction or injury to the sample. SEM/EXDA provides qualitative elemental analysis and element localisation on samples being analysed. SSIMS Static Secondary Ion Mass Spectrometry: SSIMS allows molecular identification and thin film characterization of organic and inorganic materials on surfaces. TEM Transmission Electron Microscopy: TEM is used for ultra structural characterisation of a wide range of samples. Applications include morphology, crystallographic and compositional information, including Biological TEM applications.

3 Caracterização dos Materiais Microscopy Homepage > Surface Analysis > Surface Science Capabilities Surface Analysis Laboratory Techniques Microstructural and Nanoscale Surface Analysis AES Auger Electron Spectroscopy: AES is a able to determine composition of the top few layers of a surface. AES is sensitive to low atomic number elements and all elements save hydrogen and helium. XRD X-Ray Diffraction: XRD is used for characterizing materials. The technique is used to studying powdery particles, particles in liquid suspensions or polycrystalline solids, including bulk or thin film materials. AFM Atomic Force Microscopy: AFM studies of surface topology and physical properties on a nanometre scale. Surface imaging is to near atomic resolution, measuring atomic level forces at the sample surface. Van der Waals, electrostatic, capillary, magnetic and ionic forces produce topographical images of the sample. X-Ray Photoelectron Spectroscopy: XPS determines surface elemental and functional group composition. XPS provides chemical state information from the first few atomic layers at the sample surface. XPS allows chemical composition analysis of the surface layer from 5 to 10 nanometers. SPM Scanning Probe Microscopy: SPM measures weak electrical current flowing between the probe tip and sample as they are separated at a distance. Vertical Scanning, Phase Shifting Interferometry: Vertical scanning interferometry (VSI) is a non-invasive technique used to quantify surface topography of solids such as metals, ceramics, minerals, glasses with high precision.

4 Energia / Momento Matéria Fótons Íons Átomos Elétrons Caracterização dos Materiais Propriedade a ser caracterizada Fótons Íons Átomos Elétrons Energia / Momento Matéria

5 Caracterização dos Materiais Áreas da espectroscopia

6 Caracterização dos Materiais Diagrama de energias de átomos isolados

7 Caracterização dos Materiais Modos extensionais e torcionais Diagrama de energias de sistemas moleculares

8 Absorção de radiação eletromagnética por um átomo Caracterização dos Materiais Espalhamento Raman e Rayleigh

9 Caracterização dos Materiais radiação luminosa

10 Caracterização dos Materiais radiação luminosa Técnica de bombeamento e prova (Pump-probe) Resolução temporal de pico (10-12s ) ou femtosegundos (10-15 s)

11 Caracterização dos Materiais Raios X Cobre Lei de Moseley 1 C ( Z σ ) λ =

12 Caracterização dos Materiais Raios X Fe 0.44 Pt 0.56 /Pt/SiO 2 FePt(111) 2θ = o Pt(111) 2θ = o Intensity (a.u.) θ (degree) fluorescência difração Cromo-niquel sobre prata-cobre

13 Caracterização dos Materiais Raios X difração

14 Caracterização dos Materiais Raios X Espectros de absorção de raios X EXAFS (Extended X-ray Absorption Fine Structure) XANES (X-ray Absorption Near-Edge Structure) Necessita um Síncrotron

15 Síncrotron Caracterização dos Materiais Raios X

16 Fotoelétrons emitidos por raios X Caracterização dos Materiais Raios X

17 Caracterização dos Materiais Íons PIXE (particle-induced X-ray Emission)

18 Caracterização dos Materiais Íons RBS (Rutherford Back-Scattering Analysis) Energy(MeV) Em geral, usa-se feixe de partículas alfa ou protons -Colisões elásticas determinam a massa atômica que provocou o espalhamento dos íons Channel Normalized Yield

19 Caracterização dos Materiais Íons SIMS (Secondary Ions Mass Spectrometry Analysis) Fonte de íons Esquema geral do SIMS Permite a análise composicional em profundidade, com resolução lateral de ~10 microns e sensibilidade composicional de partes por milhão (~0,1 ppm)

20 Caracterização dos Materiais Íons Em geral, íons são mais utilizados para produzir alterações estruturais ou morfológicas nos materiais (por exemplo: dopagem de semicondutores, endurecimento de metais, Feixe de Íons Focalizados (FIB),... )

21 Energia / Momento Matéria Fótons Íons Átomos Elétrons Neutrons Prótons Caracterização dos Materiais Propriedade a ser caracterizada Fótons Íons Átomos Elétrons Neutrons Prótons Energia / Momento Matéria