The Electron Microscopy Center

Just another College of Engineering site

Sample preparation

Description

The sample preparation equipment is located in ASTeCC A004. There are some standard procedures for the preparation of thin TEM samples for common materials, but many times you will have to use a known procedure as a starting point and optimize it for your material. This requires experimentation and time. The sample preparation facility can only be used for samples that are to be analyzed in our center. There is no charge for using the facility.

EMC Preparation Equipment

  • Emscope gold sputter coater
  • EmiTech K-750 Carbon coater and freeze dryer
  • Bueller Icomet 3 grinder
  • Bueller Isomet Diamond saw
  • GATAN 601 ultrasonic cutter
  • GATAN 656 dimpler
  • GATAN 691 precision ion mill
  • Fischione ion mill
  • Struers TenuPOL-5 jet polisher
  • Zeiss Optical Microscope

TEM sample preparation:

The following information is provided to help you get started in preparing TEM samples. There is no set procedure for TEM sample preparation, because there are many variables that effect results. You must research and conduct trial and error experiments to find the best procedure for your material. We have manuals for the equipment that you may copy and return. These have a lot of good information in them beside just how to operate the equipment. You should be thoroughly familiar with the relevant manuals and the operation of the equipment before you begin. You should have basic supplies, ie.grids, tweezers, and storage boxes on hand. We do not provide them. We recommend Emsdiasum LC200-Cu lacey carbon grids, cat. # 78320-5 number five tweezers, and cat. # 71150 grid storage boxes.

  • Particulate materials
    This covers particulates, nanowires, and nanotubes less than .5 micron in size. Through experience we find that a dry mount on a Lacey Carbon grid gives the best results when possible, but in some cases a wet mount is required. In this case a drop of the suspension is placed on a Lacey carbon grid. Order these grids from Emsdiasum catalog number LC-200 Cu. We do not provide them.
  • Bulk materials
    Making very thin samples from bulk can be difficult, depending on the material. In general the material will need cutting, grinding, either punching or ultrasonic cutting to 3mm diameter, then either jet polishing or dimpling, and finally possibly ion milling. There are many variables in these procedures and it is your responsibility to research the literature for preparation methods for your material and to contact other people who have done similar preparations. If you can make arrangements to use a FIB at another laboratory, it is recommended.
  • Cross sections
    Here again the preparation variables are highly dependant on the material. A number of trial and error experiments will need to be performed. Any information you can obtain from the literature or others about similar material preparation such as yours should be done well in advance so you can plan your experiments. The ultrasonic cutting manual has a lot of useful information on preparing cross sections. If you can make arrangements to use a FIB elsewhere, it is recommended