What is our logo?
Our MRSEC logo shows the arrangement of atoms at the surface of a crystal. Crystals are made up of layers, or "planes" of atoms, perfectly stacked in an ordered pattern. Because this surface has been cut at a slight angle to the crystal planes, it appears "stepped" (we call this type of surface a vicinal surface). Modern scanned-probe microscopes, such as the STM, allow us to see the atoms at the surface of a crystal, producing images very similar to this one.

University of Maryland

Materials Research Science and Engineering Center

IRG 2: Multifunctional Magnetic Oxides

Two kinds of non-centrosymmetric magnetic order that can induce ferroelectricity are illustrated.

The motion of magnetic domains walls in FeGa by application of an electric field is imaged by Lorentz TEM microscopy.

Senior Investigators

• H. Dennis Drew (leader), Physics
• Lourdes Salamanca-Riba, Materials Science & Engineering
• Ichiro Takeuchi, Materials Science & Engineering
• Sang-Wook Cheong, Physics, Rutgers
• Valery Kiryukhin, Physics, Rutgers
• Samuel Lofland, Physics, Rowan
• Jeffrey Lynn, NIST

Magnetism and ferroelectricity are essential to many forms of current technology, making multiferroic materials, where these two phenomena are intimately coupled, of great technological and fundamental importance. The discovery that even a weak magnetoelectric interaction can lead to spectacular cross-coupling effects when it induces electric polarization in a magnetically ordered state has great potential for tuneable multifunctional devices. Also, elastically coupled composite multiferroics have been developed that already demonstrate a useful magneto-electric response. The magnetic ferroelectricity occurs in ‘frustrated magnets’ with competing interactions between spins and complex magnetic orders. These fundamental and technological issues have driven the great current interest in these materials.

The goals of this research group are to understand the fundamental processes in these materials and to develop and test novel room-temperature device concepts for their exploitation in applications including ultrasensitive magnetic field sensor arrays and bi-tunable memory elements. We are using state of the art growth techniques for synthesizing single crystals and atomically controlled thin film multilayers. Combinatorial synthesis allows rapid optimization of useful properties. The science and technology of multiferroics are being addressed by a wide range of state of the art characterization tools.

Highlights

• Bilayer Graphene Photon Detector
• Atomic Resolution Imaging at 2.5 GHz using Near Field Microwave Microscopy
• Origin of Electric-field-induced Magnetization in Multiferroic HoMnO₃
• For the complete list, see the Highlights page

Publications

• View the IRG 2 publications list

IRG 2 Group Leader

H. Dennis Drew

Research Professor, Physics