Multiferroics and magnetoelectrics: new spintronic routes

Multiferroics and magnetoelectrics: new spintronic routes

Multiferroics and magnetoelectrics: new spintronic routes
W. KLEEMANN
Angewandte Physik, Universität Duisburg-Essen, 47048 Duisburg, Germany.
[email protected]
Multiferroic and magnetoelectric (ME) materials [1,2] have the potential for novel densely packed
magnetic data storage and processing devices with reduced power consumption. Actually, most
promising concepts aim at electrically controlling the giant (GMR) or tunneling magnetoresistance
(TMR) of magnetic multilayer stacks involving either tunnel barriers (magnetoelectric [6] or
multiferroic [7]) or exchange-coupled magnetoelectric pinning layers (MERAM [8]). Multiferroic TMR
devices are best suited for realizing novel four-state logics [7], if the intrinsic magnetoelectric coupling
between the magnetic and electric order parameters is weak as realized in La0.1Bi0.9MnO3 (LBMO).
Contrastingly, exchange-biased magnetoresisitive memory devices demand for large magnetoelectric
coupling as realized in Cr2O3 [9]. The physical principles and the state of the art of these concepts [10]
will be discussed.
[1] M. Fiebig, J. Phys. D 38, R123 (2005).
[2] W. Eerenstein, N.D. Mathur, J. F. Scott, Nature 442, 759 (2006).
[6] Ch. Binek, A. Hochstrat, X. Chen, P. Borisov, W. Kleemann, B. Doudin, J. Appl. Phys. 97, 10C514
(2005).
[7] M. Gajek, M. Bibes, S. Fusil, K. Bouzehouane, J. Fontcuberta, A. Barthélémy, A. Fert, Nature Mat. 6,
296 (2007).
[8] X. Chen, A. Hochstrat, P. Borisov, W. Kleemann, Appl. Phys. Lett. 89, 202508 (2006).
[9] P. Borisov, A. Hochstrat, X. Chen, W. Kleemann, Ch. Binek, Phys. Rev. Lett. 94, 117203 (2005).
[10] A. Hochstrat, X. Chen, P. Borisov, W. Kleemann, US Pat.7,719,883 B2 (2010/05/18)