Atomistic Simulation Investigation on Processing-Structure-Property Relation of Magnetic Metal Alloy Nanostructures

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

NON-TECHNICAL SUMMARY: Magnetic metal alloy nanostructures have wide applications in the fields of biomedical diagnostics, drug delivery, catalysis, mechanical actuations, and ultra-high density recording. This project will produce and disseminate new computational techniques and basic knowledge in the area of rational design of novel magnetic metal alloy nanostructures. The project is expected to impact scientific areas of materials science, physics, chemistry, biology, medical health, and computer technology. The outcomes of the project will comprise knowledge on how nanomaterial processing and crystal structure collectively determines the magnetic properties of alloy nanostructures as well as the capability to employ computation techniques for material design. To maximize the impact of the project to the broader community, the PI will incorporate the research results into curriculum enhancement, student training, industrial collaboration, and K-12 outreach program. The students involved in the project will gain advanced expertise in computational materials science. In particular, the PI will use the educational activity of this project to inspire the interests of high school students with diverse ethnic backgrounds in science and engineering disciplines. TECHNICAL SUMMARY: Switching from contemporary polycrystalline media (consisting of dozens or hundreds of grains per bit) to one single crystalline magnetic nanostructure per bit will significantly decrease the volume and accessing time for information archive. To enable this nanotechnology, the objective of this project is to accurately predict the surface segregation, atomic ordering, and magnetic properties of magnetic metal alloy nanostructures and further advance the fundamental understanding of the processing-structure-property relation for these magnetic alloy nanostructures. The proposed research activities include simulating the surface segregation process in some selected binary and ternary magnetic alloy nanostructures, analyzing the variation of atomic ordering as a function of the size, shape, composition, and processing conditions of the alloy nanostructures, predicting the magnetic properties of the alloy nanostructures with their thermodynamically equilibrated structures, and elaborating the interweaved relation among surface segregation, atomic ordering, and magnetic property of the alloy nanostructures using computational techniques. Atomistic Monte Carlo simulations will be performed to acquire the thermodynamically equilibrated configurations of the alloy nanostructures and the first-principles density functional theory calculations will be used to predict the magnetic properties of the alloy nanostructures. This work will provide knowledge for performance optimization of magnetic alloy nanostructures through tuning their composition, structure, and processing conditions. Therefore, the proposed research will strengthen our capability and enrich our knowledge in developing well-controlled magnetic metal alloy nanostructures for advancing ultra-high density recording technique.