The Center For The Accelerated Maturation of Materials

The FEI TITAN is a state-of-the-art Transmission Electron Microscope, which was installed in 2006. The important feature of this microscope is its electronic and mechanic high stability provides the sub-Angstrom (~0.7 Å) resolution in the HRTEM mode. Also, TITAN is an ideal analytical tool for applications such as STEM, EDS and EELS where high brightness and small probe is required. The microscope has a SuperTwin objective lens with a Cs of 1.2mm. It has a point resolution of 0.2nm and information limit of 0.07nm. The spatial resolution in the STEM mode is 0.13nm.

The performance of the TITAN is also very dependent on the site where it is located. Therefore, the system at the Ohio-State has been installed in a specially designed room that has minimal environmental instabilities. The microscope is located on a low-vibration platform, which is mechanically isolated from the rest of the building. The overall structure of this platform is aimed to lower both the vertical and horizontal vibrations especially in the low frequency range (0-10 Hz). For fine analytical probe performance, electromagnetic fields give rise to instabilities in the electron beam. For this reason, the reinforcement in the concrete is fiberglass rods instead of metal, and the electrical supplies in the room were all checked for ground loops and current imbalances. The vertical and horizontal AC magnetic fields around the column are reduced to values of less then 0.2 mG . The stability of the image and the microscope is very dependent on the thermal stability in the room. Measurements on-site now indicate a short-term stability in room temperature of less than 0.2o/min and long-term of less than 1o /day.

In this special location, the system achieves routine sub-Ångstrom resolution in the parallel illumination / high-resolution transmission electron microscopy (HRTEM) mode and 1.36 Ångstrom resolution in the probe / scanning transmission electron microscopy (STEM) mode.