Lecture Jeroen van den Brink
|02 september 2005||FWN-Building 5114.0004, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Prof. Dr. Jeroen van den Brink|
|Affiliation:||Instituut-Lorentz for Theoretical Physics, Leiden University|
|Title:||Magnetism versus ferroelectricity; a new route to combine both|
|Date:||Fri Sep 2, 2005|
|Telephone:||+31 50 363 4565|
Transition metal oxides with a perovskite-type structure constitute a large group of compounds. Among them are famous materials such as the prototypical ferroelectric system BaTiO3, CMR manganites and the High-Tc superconductors. Hundreds of these compounds are magnetic, and hundreds of others are ferroelectric. However, the comparison of these extensive tables shows that these two properties very seldom coexist.
Compounds with an interdependence of magnetism and ferroelectricity could be very useful: they would open a plethora of applications, for instance a switching of magnetic memory elements by electric fields. We report on a possible route to avoid this incompatibility, and show that in charge and orbitally ordered perovskites it is possible to make use of the coupling of magnetic and charge ordering to obtain ferroelectric magnets. In particular in less-than-half doped manganites there is a type of charge ordering that is intermediate between site-centered and bond-centered. Such a state breaks inversion symmetry and is predicted to be magnetic and ferroelectric1.
 D. Efremov, J. van den Brink and D. Khomskii, Nature Materials 3, 853 (2004)
|Laatst gewijzigd:||22 oktober 2012 14:30|