University of Birmingham > Talks@bham > Condensed Matter Physics Seminars > Giant magneto-elastic coupling and tricritical metamagnetism in Mn-based Pnma compounds

Giant magneto-elastic coupling and tricritical metamagnetism in Mn-based Pnma compounds

Add to your list(s) Download to your calendar using vCal

  • UserDr. Karl Sandeman, Imperial College London
  • ClockFriday 21 May 2010, 14:00-15:00
  • HousePhysics East 217.

If you have a question about this talk, please contact Elizabeth Blackburn.

Large magneto-elastic interactions are crucial to a range of new, technological materials in which multiple order parameters exist simultaneously and are coupled. These include ferromagnetic shape memory materials, multiferroics and magnetic refrigerant materials. Despite its relevance, atomically-resolved observations of large magneto-elastic coupling within a given crystal structure are very rare.

I will describe our recent high resolution neutron diffraction studies of CoMnSi, a metallic helical metamagnet in which the thermal evolution of the helimagnetic state is accompanied by a change in inter-atomic distances of up to 2%, the largest ever found in a metallic magnet [1]. Our observations lead us to a picture of competing exchange interactions at particular values of nearest-neighbour Mn-Mn separation. This subtle exchange balance is probably the key to metamagnetism in a wide range of Mn-based Pnma compounds and should enable the synthesis of new materials with tailored metamagnetic transitions [2].

[1] A. Barcza et al., cond-mat/1003.1206 [2] Z. Gercsi et al., cond-mat/1003.5193

This talk is part of the Condensed Matter Physics Seminars series.

Tell a friend about this talk:

This talk is included in these lists:

Note that ex-directory lists are not shown.


Talks@bham, University of Birmingham. Contact Us | Help and Documentation | Privacy and Publicity.
talks@bham is based on from the University of Cambridge.