For more information on my work (meant for non-scientists), please click here for powerpoint file Discussion is included in the notes section to guide you through the slides.

I am investigating a certain class of materials that show promising device applications, particularly for future computers. In these materials alone, we can change magnetic fields with electric fields or vice versa. Current computers use magnetic domains for 0's and 1's. These domains are changed by magnetic fields. The problem is that the large magnetic fields that are required to change these smaller and smaller bits require a lot of power, are slow, and are hard to localize. If we can use electric fields instead, we do not have all of these problems.

These materials are called multiferroics. Multiferroic materials exhibit two or all of the following properties: (anti)ferromagnetism, (anti)ferroelectricity, and ferroelasticity. The number of multiferroic materials is limited, particularly at room temperature. I am mainly focused on the thin film BiFeO3, because it is the only single phase room temperature multiferroic that is known today. Currently, I am investigating this and other materials by means of photoemission electron microscopy (PEEM), x-ray magnetic dichroism (XMD), and piezoresponse force microscopy (PFM), which allow me to compare and change the electric and magnetic domains in the samples. The high-resolution second harmonic generation for which I plan to set up with also allow me to do this, but with better resolution. This technique also has added benefits of being nondestructive and available without a synchrotron. Not being limited to synchrotron studies means that the technique can be set up anywhere and we will have full access instead of only a few days a year. My graduate work has been funded by the Department of Defense and the Semiconductor Research Corporation.

PHYSICS

Research Interests:

• Second harmonic generation studies in oxides, thin films and organics

• Electric control of magnetic structure

• Imaging of ferromagnetic and antiferromagnetic domains

• Exchange bias, coupling between antiferromagnets and ferromagnets

• Multifunctional materials with potential coupling with order parameters

• Piezoelectric force microscopy for the study of ferroelectric domains

• X-ray absorption spectroscopy and x-ray magnetic dichroism

• Modeling of expected dichroic contrast for different magnetic behaviors

• Internal photoemission to study spin relaxation in GaAs