This grant supports the tandem of a cryo ultramicrotome and a double tilt cooling holder used in a study of phase transformations in LiCoO2, an electrode material in Li-ion batteries. The strain acting in LiCoO2 particles between the surface and the particle center is studied by CBED. This technique allows one to obtain information on crystal symmetry and dimensions of the unit cell from small regions. The results of systematic studies of lattice strains and lattice symmetry aid in understanding the driving forces and mechanisms of observed lattice transformation. Transmission electron microscopy (TEM) specimens are prepared in cross section by ultramicrotome. The research takes the approach of investigating battery materials by TEM to the next level, crystallographic details within single powder grains. While the application of TEM techniques to battery materials is fairly recent, it has proven successful in the discovery of the transformation from hexagonal to spinel phase that was not accessible by conventional diffraction techniques (x-ray and neutron diffraction). The instruments are of use in the development of new magnetic biological tracers for virus detection. The goal of this research is to bind gold-coated Fe and Fe3O4 nanoparticles to various antibodies as biological tracers for MRI detection. This research necessitates experiments to determine whether the tracer antibodies are capable of penetrating cell membranes and capillary walls. Tissue samples must be sectioned with a cryo-microtome. Another project involves the coating of metallic nanoparticles with polymers. This is studied in the TEM at liquid nitrogen temperatures to prevent beam damage of the coating layer.
The results of these activities benefit society over a broad range: batteries are a substantial part of a technologically driven society. They operate lap top computers, cell phones and pacemakers. Batteries for medical applications need to be reliable and long lasting. In the immediate surrounding at UNO the new techniques will enhance the spectrum of possible investigations by TEM. AMRI is a joint project between the department of physics and chemistry. In many cases a crossing over to biological and medical applications and materials occurs that requires new investigation techniques. The facilities at AMRI are open to all scientists and students interested in using them. The local student population profits by working with state-of-the-art equipment on materials that stand at the forefront of materials development. Sttudents obtain an education that makes them highly qualified specialists. UNO is a university with a substantial minority student body.
