NER: Hybrid Magnetic Nanostructures

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

This collaboration between the University of Colorado at Boulder (CU) and Texas A\&M University (TAMU) will explore a new nanostructured material concept and new nanofabrication techniques for Hybrid Magnetic Nanostructures to explore predictions of dramatically novel properties. In hybrid systems, fabricated from materials with different and even mutually exclusive states, a strong mutual interaction between subsystems can dramatically change the structure and properties of the constituent materials. This approach offers unlimited horizons for qualitatively new science and technology. The main focus in this exploratory research will be Hybrid Magneto-Superconducting Nanostructures (HMSN), but, prospects for application of this concept to novel nanostructured magnet/magnet and magnet/semiconductor hybrids will also be evaluated to explore predictions of dramatically novel properties. The concept of magnet/superconductor nanostructures has been introduced by a number of researchers, including the PIs' groups, with expectation of novel physical phenomena and important properties for applications. However, experimental realization of such hybrids is far behind theory. Existing experimental results in the field have relied on nanolithographically fabricated magnetic dots on superconducting films. Nanolithography, however, is comparatively cumbersome, thus limiting further development in the field. We propose a new nanofabrication strategy: magnetic metal will be electroplated into etched pores in alumina or polycarbonate substrates to create Magnetic Nanorods (MNR) with the diameter in the nanometer range and length in the micron range. Superconducting (SC) films will be coated on the substrate, which has been polished smooth or partially etched to leave an array or protruding MNR. The dependence of the critical current versus MNR concentration, shape, size, materials and the external parameters temperature and field will be studied with the goal to optimize the FL pinning and the preparation technique. An immediate benefit is an inexpensive procedure for preparation of superconducting films with high critical current. Of broader impact is the availability of a unique HMSN system, which can have not only the theoretically predicted unusual properties, but also unexpected physical behaviour. More significantly, the fabrication technique can be readily extended to produce magnetic nanorods embedded in other types of materials (different magnetic materials or even semiconductors) to yield hybrid magnetostructures with potential for even further new physics and/or technological applications. Both senior researchers routinely involve students/postdocs from underrepresented groups