FNI 1A1 Scanning Probe Microscopes SPM History of scanning probe microscopes SPM System Overview Piezoelectric Effect Scanning Tunneling Microscope (STM) Atomic Force Microscope (AFM) Force vs. Distance Curve Scanning modes Vendors

FNI 1A2 History of Scanning Probe Microscopes Phonograph record

FNI 1A3 History of Scanning Probe Microscopes 1929 Gustev Schmalz Stylus profiler

FNI 1A4 History of Scanning Probe Microscopes 1971 Russel Young Topographiner A non-contact stylus profiler

FNI 1A5 History of Scanning Probe Microscopes 1981 Gerd Binnig & Heinrich Rohrer Scanning Tunneling Microscope (STM)

FNI 1A6 History of Scanning Probe Microscopes Atomic Force Microscope (AFM/SFM) Gerd Binnig, Calvin Quate & Christoph Gerber 1986

FNI 1A7 SPM System Overview

FNI 1A8 SPM Scan Head STM AFM Non Contact AFM Contact AFM Lateral Force Microscopy Force Modulation Laser should be switched on to operate

FNI 1A9 SPM Scan Head First: Adjust cantilever alignment so laser is aligned on the cantilever Second: Adjust detector alignment until red lights are out and green light is on.

FNI 1A10 Pre-Mounted AFM Probe Tip

FNI 1A11 Cartridges AFM Cartridge STM Cartridge

FNI 1A12 Digital Voltmeters

FNI 1A13 A+B Should be Maximized A-B Should be Minimized A = 1+3 B = Top = 1+2 Bottom = 3+4 LFM records Top-Bottom and should be minimized Photodetector

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FNI 1A19 Scanning Tunneling Microscope Applications System Components Tube scanner Piezoelectric effect Theory of operation Operating modes Advantages & Disadvantages

FNI 1A20 Applications High resolution images at atomic resolution. Ability to manipulate individual atoms.

FNI 1A21 STM System Components

FNI 1A22 Piezoelectric tube scanner Piezoelectric materials are used to create a tube scanner. This forms one of the basic components of scanning probe microscopes. These can be used to manipulate an object in three dimensions under electronic control.

FNI 1A23 Piezoelectric Effect Certain materials exhibit what is called the piezoelectric effect. (Demo) This is an effect where changing the size of an object results in a voltage being generated by the object. Conversely when a voltage is applied to a piezoelectric object then the size of the object changes.

FNI 1A24 Piezoelectric Effect Piezoelectric materials have an asymmetric unit cell like a dipole. If these crystals are grown in the presence of a strong electric field then the crystal grains will align and the piezoelectric effect is created. PZT: Lead zirconium titanate is one of the most common piezoelectric materials.

FNI 1A25 Unit Cell with Dipole Cubic T > T c Tetragonal T < T c The central atom is displaced resulting in a unit cell with a dipole moment.

FNI 1A26 Piezoelectric Effect Crystal grains structure Grown in an electric field Unit cell dipoles align Not grown in an electric field Random orientation

FNI 1A27 STM Theory of operation Tunneling Current

FNI 1A28 Scanning Tunneling Microscope

FNI 1A29 Operating modes Constant height mode  Current changes exponentially  Requires a smooth surface Constant current mode  Beware of insulators

FNI 1A30 STM Advantages & Disadvantages Advantages  Able to obtain very high resolution images of conductors and semiconductors.  Probe tips can be made out of wire.  Inexpensive to purchase ~ $10,000 Disadvantages  Will not work with insulators.  If there are insulating materials present on the sample you can crash the tip.  Often need to be used under vacuum.

FNI 1A31 Scanning Tunneling Microscope Applications System Components Tube scanner Piezoelectric effect Theory of operation Operating modes Advantages & Disadvantages

FNI 1A32 Atomic Force Microscope System Components Force vs. Distance Performance & Images Scanning Modes & Probe Tips Vendors

FNI 1A33 AFM System Components Demo

FNI 1A34 Force vs. Distance

FNI 1A35 Performance The piezoelectric tubes have a movement resolution of 1 nm/volt. Magnifications of 5,000,000x can be achieved. Resolution of 10 pm Can operate in air and under liquids Atomic force microscopes can be used on many different surfaces. AFM is a versatile and easy to use tool. Images AFM Activity WS 13

FNI 1A36 Scanning Modes and Probe Tips Standard probe tips High resolution probe tips Magnetic force microscopy Frictional force microscopy/Lateral force microscopy Elasticity/hardness measurements/Force modulation microscopy Scanning Capacitance Thermal scanning microscopy – two different metals/ thermo couple Near-field Scanning Optical Microscopy/Light funnel Piezoelectric cantilever Electrostatic force microscopy Dip pen nanolithography Surface oxidation Many different companies make probe tips for scanning microscopes.

FNI 1A37 Scanning Probe Microscope Vendors Veeco JEOL Nanoscience Instruments Asylum Research JPK Instruments Molecular Imaging Nanofactory Instruments Nanotec Electronica NT-MDT Quesant WITec Pacific Nanotechnology Nanoics Imaging Schaefer-TEC Windsor Scientific LOT Oriel Ltd oriel.com/uk/htm/all/home01.phphttp:// oriel.com/uk/htm/all/home01.php Atomic Force Mikro Masch Surface Imaging Systems gmbh.com/ gmbh.com/ Physik Instrumente Accurion Advanced Surface Microscopy Hysitron Infinitesima Nanograph Systems Nanonis ml ml PSIA Triple-O Microscopy Bioforce

FNI 1A38 Scanning Probe Microscopes System Components Force vs. Distance Performance & Images Scanning Modes & Probe Tips Vendors

FNI 1A39 Links karlsruhe.de/forschung/pzt_webseiten/eng/basics/ferro_main_eng.ht ml karlsruhe.de/forschung/pzt_webseiten/eng/basics/ferro_main_eng.ht ml c.htm c.htm