Research Focus

organic thin films in gas sensors and photovoltaics

Phthalocyanines belong to a diverse family of organic semiconductors. At the center of such a molecule is usually a metal ion, such as Cu, Fe, Co, or Zn, for example. Phthalocyanines are currently used as dyes, gas sensors, and photoconductors. I am interested in understanding the structural properties, and charge transport properties, as well as the low-dimensional magnetic properties of iron phthalocyanine.

magnetic vortices

Magnetic vortices can be nanodots larger than a single domain, but not large enough for a domain wall to form. I have made magnetic Co vortices that typically measure 400 to 500nm in diameter. I am interested in understanding the interactions of magnetic vortices with a superconductor.

exchange bias

Here it refers to the interaction at the interface between a ferromagnet and an antiferromagnet. Through cooling such a bilayer in a magnetic field below the Neel temperature of the antiferromagnet (Curie temperature is assumed to be larger than the Neel temperature), a magnetic unidirectional anisotropy is induced. This anisotropy pins the ferromagnet in the cooling field direction, and breaks the symmetry of the magnetic hysteresis loop. I have studied the system of Co/CoO and you can read more in my dissertation with the title "Exchange Bias investigated with Anisotropic Magnetoresistance (AMR)". I have made contributions to the understanding of the magnetization reversal process in exchange biased system, the training effect, and the local pinning field strength.