Dresden 2003 – wissenschaftliches Programm
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MA: Magnetismus
MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)
MA 14.112: Poster
Dienstag, 25. März 2003, 15:15–19:15, Zelt
Universal behavior of magnetic phase transitions in the Mn sublattice of RxR′1−xMn2X2 (R, R′: rare earth; X: Si, Ge) compounds — •Eyüp Duman1, Mehmet Acet1, İlker Dinçer2, Ayhan Elmali2, and Yalçin Elerman2 — 1Tieftemperaturphysik, Gerhard-Mercator Universität Duisburg, D-47048 Duisburg, Germany — 2Dept. of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara, Turkey
The interaction between 3d and 4f sublattices in RMn2X2, where R is a rare earth element and X is Si or Ge, leads to a variety of spin configurations. When R is a light rare-earth, the interlayer magnetic coupling of the Mn sublattice is ferromagnetic, whereas it is antiferromagnetic in the case when R is a heavy rare earth. At low temperatures, the rare earth sublattice also orders and reconfigures the ordering in the Mn sublattice. We have investigated the magnetic properties of R1−xR′xMn2X2 for various combinations of rare earth elements R and R′ by examining the evolution of the features in the temperature dependence of the low field magnetization. By making use of the known magnetic structure of the end compositions x=0 and x=1, determined by neutron diffraction and Mössbauer studies, the results of low field magnetization measurements can give information on the magnetic structure of the compounds at intermediate concentrations. The results for all combinations of rare earths R and R′ are summarized in a general magnetic phase diagram. Furthermore, the lattice parameter dependence of the transition temperatures is clearly found to be almost independent of the type of R or R′ incorporated in the sample.