Date/Time
Date(s) - 08/11/2006
3:30 pm - 4:30 pm

Title: A Square Lattice Becomes a High-Temperature Superconductor. What About a Triangular Lattice in a Battery Material?

Speaker: Dr. Takashi Imai

Institute: McMaster University

Location: ABB 102

Description:

Recently, material scientists working on battery applications discovered a new superconductor by soaking a layered sodium cobalt oxide Na(x)CoO(2) in water. It is still a mystery as to how the electrical resistance of a wet cobalt oxide becomes zero at a cryogenic temperature. It is well known that high-temperature superconductivity takes place primarily in a square lattice formed by copper ions carrying an electron spin of 1/2. On the other hand, the cobalt ions in this battery material form a triangular lattice of spin 1/2. How can we understand the physics of this new intriguing material? This seminar will describe results obtained from nuclear magnetic resonance (NMR) technique.

References : F. Ning et al., Phys. Rev. Lett. 93, 237201 (2004). F. Ning and T. Imai, Phys. Rev. Lett. 94, 227004 (2005).