(AASERT-93) Spatially-Resolved Spectroscopy and Imaging of Magnetic Nanostructures.

Abstract : During the grant period, Mr David Tulchinsky has been responsible for developing and applying new experimental techniques for probing the electronic and magnetic behavior of nanometer-scale structures with a high degree of temporal and spatial resolution. To this end, he has successfully designed a new family of digital magnetic semiconductor heterostructures and demonstrated the existence of digitally-fabricated quantum states using II-VI ZnSe/MnSe materials. These studies involved the construction of a femtosecond-resolved upconversion luminescence spectroscopy system to monitor carrier dynamics at low temperatures (1- 300 K) and in relatively large magnetic fields (8T). In addition, he has been able to pattern these truly two-dimensional magnetic nanostructures into quasi-1D and zero-D systems using the focussed ion beam facility in the NSF Science and Technology Center at UCSB (QUEST). Cathodoluminescence measurements show structures as small as 50 nm may be fabricated for study in this fashion. Mr Tulchinsky received his Ph.D. in experimental physics based on the projects described below. He was immediately recruited as a postdoctoral researcher by scientists in the Electron Physics Group at NIST in Gaithersburg, MD. Due to the success of his graduate work under the AASERT program, he subsequently was awarded a NRC Postdoctoral Fellowship to begin scanning electron beam polarization studies of low dimensional metallic heterostructures for science and technological applications.