Log in to iLab to see the schedule and availability or email Dr. Julian Sabisch (jsabisch@ou.edu) for a consultation.
The TEM Capabilities document (PDF) provides a graphical overview our TEM capabilities.
We're happy to answer any questions and work with you to acquire new caapabilities.
Located in GLCH room 38 (basement) | Availability
Transmission electron microscopy examines structure by passing electrons through the specimen. The image is formed as a shadow of the specimen on a phosphorescent screen. In order for electrons to pass through the specimen, it must be very thin (usually less than 100 nanometers or approx. 1/25,000 inch) thick. High resolution samples must be at least 1/5 this thickness to approach the resolution that this microscope is capable of. Specimen preparation requires considerable precision equipment, time and skill. TEM is typically used to examine the internal organization of objects of many kinds, but typically extremely thin and very clean. The JEOL 2010F is used for nanotechnology applications requiring higher resolution than the JEOL 2000 and Zeiss 10. Clean specimens and high-resolution imaging methods must be used to optimize samples.
High resolution is available for ideal samples (To see atoms or atom stacks requires minimal thickness (to a couple of atoms thickness for best results)
High resolution transmission electron imaging typically requires a field emission source, a high accelerating voltage, and a thin crystalline specimen often only a few atomic layers thick. This is often achieved by grinding or etching a sample to several micrometers in thickness and then bombarding them with an ion beam to remove atoms one by one, using the imparted energy of the ion to displace an atom until the correct thickness is achieved. Below is a Si(110) crystal often used as an ideal specimen to characterize a non-aberration corrected microscope's resolution capabilities . The raw image (below) shows the so-called silicon dumbbells characteristic of this material. This image was taken with no noise in the building at 5 am.
The image was then processed to remove random noise and enhance periodic elements. Thus, aspects of the crystal structure can be directly observed and measured.
Located in GLCH room 221 (2nd floor hallway by elevators) | Availability
Transmission electron microscopy examines structures by passing electrons through the specimen. The image is formed as a shadow of the specimen on a phosphorescent screen. In order for electrons to pass through the specimen, it must be very thin (usually less than 100 nanometers or approx. 1/25,000 inch) thick. This requires considerable preparation equipment, time and skill. TEM is typically used to examine the internal structure of objects. The JEOL 2000 is used for materials sciences applications and biological applications requiring higher resolution than the Zeiss 10. It is a stable workhorse microscope that is quite flexible for transmission, scanning, and X-ray spectroscopy. In addtion, it has a Gatan (1k x 1k) digital camera installed.
Gatan cryo-TEM specimen holder (to -150°C)