NSF Award
1105474
TECHNICAL SUMMARY<br/><br/>This award supports theoretical and computational research that is aimed at first principles modeling of organic-based magnetic and multiferroic tunnel junctions. The field of spintronics has been successful in producing magnetoresistive devices for magnetic memory and sensor applications. These employ giant magnetoresistance or tunneling magnetoresistance phenomena that provide a sizable change of resistance in response to altering magnetic alignment of the two ferromagnetic electrodes in a spin valve or a magnetic tunnel junction. Organic materials are considered promising for applications in spintronics due to their long spin-relaxation times. They also have other advantages, such as virtually unlimited chemical variability and relatively low production costs. Most studies of organic materials for spintronics have so far focused on non-polar dielectrics or semiconductors serving as passive elements in spin transport devices. In this project the PI will investigate the possibility of producing novel functionality by using organic materials in spintronic and multifunctional devices, in particular magnetic and multiferroic tunnel junctions with organic barriers.<br/><br/>Organic materials used as barriers in magnetic tunnel junctions offer immediate benefits such as sharper interfaces and smaller leakage current. The PI will investigate the properties of magnetic tunnel junctions with dielectric organic barriers. Of particular interest will be the structure of the metal-organic interface, the spin polarization, and the size and sign of the tunneling magnetoresistance effect. The PI will also seek to provide a new degree of freedom in the functionality of magnetoresistive devices by replacing the dielectric organic barrier with a ferroelectric one resulting in a multiferroic junction. Furthermore, the PI will investigate the possibility of tailoring the surface magnetic anisotropy of a magnetic film by an adjacent organic ferroelectric to electrically control the magnetization orientation, which could yield entirely new device concepts, such as electric field-controlled magnetic data storage. The PI also aimes to elucidate microscopic mechanisms responsible for conductance in organic materials with the goal of making all-organic electronics.<br/><br/>This award also supports training graduate as well as undergraduate students in the area of computational condensed matter physics. This training will provide the students valuable experience in cutting-edge research which will be conducive to future employment in leading industrial and academic laboratories. In addition, the PI will develop special topics courses in the field of electronic structure theory that will be offered at his institution and made available through a new nanoscience hub. There will be a particular emphasis on the involvement of underrepresented Hispanic students in the PI's research activities. This award contributes to the PI's efforts to improve the cyberinfrastructure and foster computational science at the University of Puerto Rico.<br/><br/>NONTECHNICAL SUMMARY<br/><br/>This award supports theoretical and computational research and education in the area of materials physics. There is a strong industry demand in new materials sensitive to both electric and magnetic fields. These find applications in high-density low-power electronics capable of retaining stored information even when not powered. Such applications require smaller, faster, and more powerful devices with longer battery life. The PI will model materials on computers to aid the experimental search for functional materials. This effort benefits from theoretical and computational tools that have become increasingly more powerful, and offer reasonable accuracy to test realistic material systems resulting. The PI will investigate the incorporation of organic materials in electronic devices for memory and storage applications. Organic materials, which are made predominantly of light elements such as carbon, hydrogen, and oxygen, have the important property that they can preserve the magnetic orientation of the electron over long distances. This property, in addition to the very large chemical and functional variety offered by these materials could be very useful for applications on spin-based electronics and to engineer new functionality in organic-based materials and interfaces. The PI's computational investigations are aimed to stimulate experimental research on organic-based multifunctional devices and memories. <br/><br/>This award also supports training graduate as well as undergraduate students in the area of computational condensed matter physics. This training will provide the students valuable experience in cutting-edge research which will be conducive to future employment in leading industrial and academic laboratories. In addition, the PI will develop special topics courses in the field of electronic structure theory that will be offered at his institution and made available through a new nanoscience hub. There will be a particular emphasis on the involvement of underrepresented Hispanic students in the PI's research activities. This award contributes to the PI's efforts to improve the cyberinfrastructure and foster computational science at the University of Puerto Rico.
