Methods

Over the last decades the field of electron microscopy has improved not only with respect to higher performance such as better resolution, but also establishment of new techniques. At FELMI-ZFE we participate in method development with both via academic research as well as cooperations with manufacturers of microscopes and analytical equipment.

 

Energy filtering and EELS techniques

Energy Filtered TEM (EFTEM) and Electron Energy Loss Spectroscopy treveal chemical information about a specimen. FELMI-ZFE scientists have contributed significantly to the development of EFTEM and EELS techniques and spectrometers over the last decades.

  • Grogger, W.; Varela, M.; Ristau, R.; Schaffer, B.; Hofer, F.; Krishnan, K.: Energy-filtering transmission electron microscopy on the nanometer length scale. – in: Journal of electron spectroscopy and related phenomena 143 (2005) 1-2, S. 139 – 147
  • Riegler, K.; Kothleitner, G.: EELS detection limits revisited: Ruby — a case study. – in: Ultramicroscopy 110 (2010) , S. 1004 – 1013

 

3D-techniques using in situ ultramicrotomy in the ESEM, X-ray imaging in the FIB and electron tomography in the TEM

While conventional electron microscop methods usually deliver two-dimensional projections of a sample 3D-methods help to gain a deeper insight into the spatial structure of a specimen. A variety of methods was developed at FELMI-ZFE for the investigation of specimens of different dimensions with according resolutions.

  • Zankel, A.; Kraus, B.; Pölt, P.; Ingolic, E.; Schaffer, M.: Ultramicrotomy in the ESEM, a versatile method for materials and life sciences. – in: Journal of microscopy (2009) 233 , S. 140 – 148
  • Schaffer, M.; Wagner, J.; Schaffer, B.; Schmied, M.; Mulders, H.: Automated three-dimensional X-ray analysis using a dual-beam FIB. – in: Ultramicroscopy 107 (2007) , S. 587 – 597

 

Environmental SEM

The Environmental Scanning Electron Microscope (ESEM) overcomes the restrictions of a conventional SEM. Non-conductive specimens (e.g. polymers or biological samples) can be studied, even in situ tests can be performed using special tools like a tensile stage, a heating stage or Peltier cooling mountings of different geometries. Furthermore samples can be investigated in a wet environment, allowing condensation or crystallization.

  • Pölt, P.; Zankel, A.; Gahleitner, M.; Ingolic, E.; Grein, C.: Tensile tests in the enviromental scanning electron microscope (ESEM).Part1. – in: Polymer 51 (2010) , S. 3203 – 3212
  • Rattenberger, J.; Wagner, J.; Schröttner, H.; Mitsche, S.; Zankel, A.: A Method to Measure the Total Scattering Cross Section and Effective Beam Gas Path Length in a Low-Vacuum SEM. – in: Scanning (2009) 31 , S. 1 – 7

 

FIB

Focused Ion Beam (FIB) is a versatile tool for both sample preparation as well as for the fabrication of nanostructures. However, at FELMI-ZFE FIB related scientific research is improving the instrument and the applied techniques FIB for sample preparation as well as for nanostructuring.

  • Sezen, M.; Plank, H.; Nellen, P.; Meier, S.; Chernev, B. S.; Grogger, W.; Fisslthaler, E.; List, E.; Scherf, U.; Pölt, P.: Ion beam degradation analysis of poly(3-hexylthiophene) (P3HT): Can cryo-FIB minimize irradiation damage? . – in: Physical chemistry, chemical physics 11 (2009) , S. 5130 – 5133
  • Rogers, M.; Langford, R.: In situ lift-out: Steps to improve yield and a comparison with other FIB TEM sample preparation techniques. – in: Micron (2008) 39 , S. 1325 – 1330