Materials Research Science and Engineering Center

Research - IRG1

IRG 1:

Nanoscale Magnetism: Structures, Materials and Phenomena

The goal of this IRG is to advance our understanding of exciting topics relevant to several grand challenges in nanomagnetism and nanoscience. These include: 1) Quantum understanding of spin-polarized matter at the 1-10 nm scale, which bridges the gap between molecular and macroscopic levels 2) Complexity in fabrication and integration of top-down and self-assembled nanomagnetic structures; 3) Ultra-high-density information storage; 4) Nanomagnetic basis for magnetologic, spintronic, and spin qubit devices; 5) Ultra-strong permanent magnets; and 6) Ultra-small biomagnetic and other sensors. The length scale involved is one where new quantum approaches and simulations are needed, and where novel “superatomic” species may lead to new phenomena and magnetic properties. Complex surfaces and interfaces are of extreme importance and the synthesis and fabrication of the nanostructures are equally critical as the theoretical and characterization portions of the research. In addition to the basic-science aspects of the work, there are opportunities for major technological implications in information storage and processing, energy production and conservation, defense, and medicine.
This IRG brings a powerful combination of theoretical and experimental expertise to bear on several of the above-mentioned challenges.

IRG 1 Research Areas:

A. Novel Magnetic Clusters, Nanostructures and Phenomena:

The objective of this research is to study the fabrication and properties of relatively complex nanoclusters, including alloy, compound, core-shell, and two-phase structures. These clusters are likely to have novel properties and serve as building blocks for cluster-assembled materials with unprecedented properties.
The synthetic aspects of cluster-assembled materials have been a challenge, and studies are urgently needed of cluster production and deposition, chemical synthesis of cluster-containing solids, and self-assembly of clusters. We are pursuing these ideas with specific focus on nanomagnetic materials and structures.

Topics:

Electronic Structure and Magnetism of Novel Magnetic Clusters
Exchange Interactions and Properties of Cluster-Assembled Nanocomposites
Magnetic Nanostructures Controlled by External Stimuli
Ultra-High-Sensitivity Magnetometry of Nanostructures

B. Interactions and Dynamics in Complex Nanomagnetic Systems:

This part of IRG 1 is aimed at exploring novel magnetic structures produced by self assembly on surfaces; investigate exchange-coupled heterostructures, which permit the control of properties such as thermal stability and coercivity; and study the important issues involved in control and speed of magnetization reversal in nanostructures.
Progress in these objectives is essential to determine the ultimate physical limits for magnetism-based technologies including data storage, magnetologic and spintronics. This endeavor is including identifying conditions for the stabilization of magnetization in particles of extremely reduced magnetic volume at room temperature, determining the extent to which exchange-coupled magnetic nanostructures can be fabricated with controlled properties and behaviors, and understanding and controlling the fast and complex reversal processes implicit in nanoscale structures and devices.

Topics:

Self-Assembled Magnetic Nanostructures
Exchange-Coupled Heterostructures
Magnetization Dynamics of Nanomagnetic Structures

IRG 1 Highlights:

Published 2008: “Simple Models of Magnetism” by Ralph Skomski (Oxford University Press) (March 2008).

Books on Nanomagnetism 2006 (published by Springer, Berlin):
“Advanced Magnetic Nanostructures”,
edited by David Sellmyer and Ralph Skomski
“Handbook of Advanced Magnetic Materials”,
edited by Yi Liu, D. J. Sellmyer, and Daisuke Shindo

The Most Down-Loaded AIP Paper 2004 (in a Two-Month Period)
“Nanotube Magnetism” (Y. C. Sui, R. Skomski, K. D. Sorge, and D. J. Sellmyer)

Journal of Physics: Condensed Matter: Top Paper 2003
“Nanomagnetics” (R. Skomski)
Selected as one of the top 50 papers ever published in the field of nanotechnology theory and modeling, and included in a reprint volume 2006.