Scanning Probe Microscopy (SPM)

The scanning probe suite comprises a variety of instruments with complementary capabilities that enable the measurement of sample topography down to atomic resolution, local electromagnetic properties, and nanomechanical properties.

ATOMIC FORCE MICROSCOPY (AFM)

AFMs are available for scanning in air, other gases, or liquids with a wide variety of imaging and measurement modes, plus nanomanipulation. All instruments have sub-angstrom vertical resolution (lateral resolution is generally limited by the tip geometry, not the instrument).

Instrumentation for Atomic Force Microscopy:

  • Asylum Research MFP-3D AFM (2 instruments) | 0014 Materials Research Laboratory
    These two AFMs from Asylum Research feature closed-loop, low noise, high precision scanners, with Q-controlled AC modes (with phase imaging), piezo response imaging, contact mode with lateral force, and detailed force-distance measurements. These systems allow scanning in air or liquid environments, and have extensive nanomanipulation and nanolithography capabilities. Maximum lateral scan size on these instruments is 90 µm x 90 µm, and maximum vertical range is 15 µm.

           In addition to modes requiring no additional hardware, the MFP-3D-SA instruments have the
           following accessories and upgrades:

                         ORCA conductive AFM
                         Scanning Microwave Impedance Microscopy
                         PolymerHeater (up to 300 °C)
                         BioHeater with associated Environmental Controller
                         Closed fluid cell

  • Asylum Research Cypher | 0014 Materials Research Laboratory
    The Cypher is a state-of-the-art AFM from Asylum Research, featuring exceptionally low noise and fast scanning capabilities in addition to advanced scanning modes in air or liquid environments. Maximum lateral scan size on this instrument is 30 µm x 30 µm, and maximum vertical range is 5 µm.

           In addition to modes requiring no additional hardware, the Cypher has the following
           accessories and upgrades:

                          AM-FM viscoelastic mapping
                          Contact Resonance viscoelastic mapping
                          HV-PFM (piezoresponse force microscopy)
                          Droplet cantilever holder
                          Air Temperature Controller
                          blueDrive photothermal excitation for improved performance in liquid
                          Scanning Tunneling Microscopy

Staff Contact

Kathy Walsh
(217) 300-6662

AFM tip distributors

NOTE: Commonly used tips and sample supplies are available for purchase in the MRL storeroom.
We most commonly use BS-Tap300Al tapping tips from BudgetSensors (very inexpensive but good), and for extra sharp tips, SuperSharpSilicon from Nanosensors. Both of these are carried in the storeroom.

Some other good sources of AFM tips:

SCANNING TUNNELING MICROSCOPY (STM)

In Scanning Tunneling Microscopy (STM), an electrically biased tip is scanned very close to a surface (about an atomic diameter away). The current flow between the tip and the sample (due to quantum tunneling) strongly depends on the tip-surface gap; this relationship can be used to generate a surface topography map. Atomic-scale topographic resolution is achievable. All samples for STM must be at least somewhat electrically conductive.

Instrumentation for Scanning Tunneling Microscopy:

  • Asylum Research Cypher STM | 0014 Materials Research Laboratory
    STM mode on the Cypher serves in part as a testbed for determining whether STM is a viable experimental technique for samples before investing effort into UHV STM measurements. Additionally, the ambient conditions on this instrument permit STM measurements of samples which may not respond well to vacuum environments.

Staff Contact

Kathy Walsh
(217) 300-6662
 

HYSITRON TI-950 TRIBOINDENTER

The Hysitron TI 950 TriboIndenter at the Materials Research Laboratory is a versatile instrument with capabilities beyond traditional quasistatic nanoindentation. In addition to a standard transducer which can apply micronewton-to-few-mN loads over a displacement range of several micrometers, a high load transducer allows indents to be made at loads of up to 2.8 N over a displacement of up to 90 microns. Both of these transducers are capable of scratch testing in addition to indentation. Additional capabilities available on this instrument include nanoDMA, nanoECR, and acoustic emission. nanoDMA measurements investigate viscoelastic properties of materials by applying a small modulation to the load during the indent. nanoECR measurements provide information about electrical resistance of the sample as a function of applied load and contact area. An acoustic emission sensor in close proximity to the tip can detect acoustic waves due to cracking in samples as they are indented, giving information about fracture mechanisms. The standard and nanoDMA transducers are compatible with a heating stage that can raise the sample temperature to approximately 400 degrees C. Automated measurement routines permit large numbers of indents to be made to enable good measurement statistics, and in situ scanning probe imaging permits precise placement of indents on nanoscale features.

Location: 0013 Supercon

Staff Contact

Kathy Walsh
(217) 300-6662

PIUMA NANOINDENTER

The Optics11 Piuma soft material nanoindenter uses cantilever-based nanoindentation (similar to AFM force curves) to determine the Young's modulus of samples with moduli from a few tens of pascal to 1 GPa.  Maximum displacement during the indent is 20 microns.  Probe tips are spherical glass beads with diameters of 10-50 microns, enabling operation of the instrument as a simplified cousin of colloidal probe AFM.  Operation in air or fluid and automated grids of indentations are simple to set up.  

Location: Room 248 MRL

Staff Contact

Natalie Becerra-Stasiewicz
(217) 265-8419

Similar Techniques

Information regarding the Sloan Dektak3 ST stylus surface profilometer can be found at http://mrl.illinois.edu/facilities/center-microanalysis-materials/cmm-in....

Information about the neaspec nanoFTIR/NIM can be found under the AFM,NANO-FTIR, SSNOM description at http://mrl.illinois.edu/facilities/laser-and-spectroscopy-facility/lsf-instruments/microscopy