Neutron Diffraction Studies on Magnetoelectric Multiferroics
Magnetism and ferroelectricity are essential to many forms of current technology. The multiferroic-based device could provide an efficient link between conventional electronic logic and spin-based logic, which offers the potential for significantly reduced energy consumption compared to present-day integrated circuits. An important number of magnetoelectric multiferroics has the general chemical formula ABO3 and crystallizes in a perovskite or perovskite-related structure.
The magnetoelectric coupling in these multiferroic materials is so strong that electric polarization can be reversed by an external magnetic field. This breakthrough can open new routes for the design of magneto-electric devices. Due to the absence of single crystals, the structure investigations in multiferrorics are still in the infancy. Isothermal compression of the sample leads to a vanishing of the ferroelectricity through a phase transition sequence which is identical to that encountered on increasing temperature run. However compared to temperature effects specific features may occur under pressure, e.g. the order of the transitions gradually changes from first to second order. Although the perovskite multiferrorics are very interesting compounds, little is known about their behaviors under pressure, specifically crystallographic data and equations of state are still missing. High-pressure neutron diffraction measurements on multiferroric oxides can provide accurate structural characteristic. The data are required for a better understanding of the behavior under strong compression and are important to understanding of the magnetoelastic coupling and its role played in the mechanism of these multiferrorics.
Science Thrust Area
- Sci. Thrust Areas: Superconducting, Electronic & Magnetic Materials
- Technology Task Force Teams: Neutrons
- Laboratory or Institution: NIST, SNS, Oakridge Tenn.
- Personnel: Xiao-Jia Chen, Malcolm Guthrie
- National Laboratory Partners: Chris Tulk, SNS
- Other Collaborators: A. M. d. Santos, SNS, Jamie Molaison, SNS, Q. Z. Huang