The continued evolution of portable electronic devices and micro-electro-mechanical systems (MEMS) requires multi-functional microscale energy sources that have high power, high energy, long cycle life, and the adaptability to various substrates.

Background: A bar magnet has two poles, denoted as +1 and -1 magnetic charges.  Patterned structuresconsist of many magnets (Fig. 1), where the square array (Fig. 1a) does not, whereas the honeycomb (Fig. 1b) has, net magnetic charges (or magnetic monopoles).  Under a magnetic field these local magnetic monopoles will move (Fig. 1c).  This latter structure is called “spin ice”, because it has a large number of nearly degenerate configurations. This work: We propose a theoretical model of the dynamics in artificial spin ice under an applied

Background: CoFeB-MgO magnetic tunnel junctions (MTJs) are leading spintronic devices that relies on quantum Mechanical tunneling of electrons from one magnetic metal (CoFeB) to another across an insulating barrier of MgO. The electrical resistance of such MTJs is dictated by the orientation of the two CoFeB metals, parallel or antiparallel.   The performance of MTJ is measured by tunneling magnetoresistance (TMR), which is only 20% initially, but greatly increases to 200% after high temperature annealing (Fig. 1). We reveal the evolution of the local structure during annealing.

Since 2006, members of the University of Chicago MRSEC have visited the Exploratorium and hosted reverse-visits by Exploratorium artists and scientists. The long-term goal is the realization of MRSEC-inspired exhibits on the Exploratorium floor. The picture on the left is of Shawn Lani (formerly, Exploratorium) and Sid Nagel discussing the beautiful and compelling structures made by a vibrated cornstarch/water mixture.

Ordering of spherical particles represents a fundamental topic in materials science and engineering ranging from the sub-nanometer scale packing of atoms in simple crystals to micron sized assemblies of colloids.

On the left is a magnetic force microscope (MFM) image of a CoFeB patterned film, and on the right is a representation of the micromagnetics (distribution of local magnetic moments). The pattern

Graphene, a single atom-thin sheet of carbon, can be used to make ultra-fast electronics. Researchers at the University of Maryland Materials Research Science and Engineering Center (MRSEC) are collaborating with the U.S. Naval Research Laboratory (NRL) to understand how graphene forms on the surface of silicon carbide.  Growing graphene on silicon carbide could provide a platform to manufacture high speed graphene transistors which could find uses in applications ranging from advanced radar to miniaturized cellphones.  

A new class of materials shows great promise for next generation electronics applications.  Topological insulators have been heralded for unique properties that may prove crucial to the successful development of devices in the emerging fields of spintronics and quantum computing. Scientists are further excited about the prospect of investigating new and peculiar fundamental physics in these materials.