Regensburg 2007 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 15: Poster:ThinFilms(1-33),Transp.(34-49),ExchBias(50-56),
Spindynamics(57-70),Micro-nanostr.Mat.(71-82),
Particles/Clust.(83-88), Mag.Imag./Surface(89-96),
Spinelectronics(97-109), Theory/Micromag.(110-116),
Spinstruct/Phasetr.(117-128),Magn.Mat.(129-139),
Aniso.+Measuring(140-145), MolMag.(146-152),
MSMA(153-156)
MA 15.120: Poster
Dienstag, 27. März 2007, 15:00–19:00, Poster A
Spin-flop transition in uniaxial antiferromagnets — •Alexei N. Bogdanov1,2, Alexander V. Zhuravlev2, and Ulrich K. Rößler1 — 1IFW Dresden — 2Donetsk Institute for Physics and Technology
A comprehensive phenomenological theory of the spin-flop reorientation in easy-axis antiferromagnets has been developed [1]. The characteristic hierarchy of exchange and relativistic interactions in this class of antiferromagnets causes a strongly pronounced two-scale character of their magnetic properties. In contrast to the major part of the magnetic phase diagram, near the spin-flop field magnetic properties are determined by weak higher-order intrinsic interactions. In this region the system can be described by an effective model akin to uniaxial ferromagnets. The analysis of magnetic-field-driven reorientation and the concomitant multidomain states provides a consistent picture of the magnetization processes near the spin-flop field. We elucidate such remarkable spin-flop phenomena as reentrance of phases in the coexistence region, enhanced magnetic susceptibility, and complex magnetization processes. The validity of the theoretical results has been demonstrated by experimental investigations of the spin-flop transition in the orthorhombic layered antiferromagnet (C2H5NH3)2CuCl4 [1,2]. The theory developed in this work can be adopted for investigations on synthetic antiferromagnets and exchange-biased systems [3].
[1] A. N. Bogdanov, A. V. Zhuravlev, U.K. Rößler, cond-mat/0609648. [2] A. N. Bogdanov, A. V. Zhuravlev, I.V. Zhikharev, U.K. Rößler, J. Magn. Magn. Mater. 290-291, 768 (2005). [3]. A. N. Bogdanov, U. K. Rößler, Appl. Phys. Lett. 89 (2006) 163109.