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 15.125: Poster
Dienstag, 27. März 2007, 15:00–19:00, Poster A
Magnetic phases in Y_xCa_1-xMnO_3 — •Uwe Amann1,2,3, Clemens Ritter2, Dietmar Hohlwein1,3, Andreas Pfrommer1, and Jörg Ihringer1 — 1Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany — 2Institut Laue-Langevine, 38100 Grenoble, France — 3SF2/Magnetism, Hahn-Meitner Institut, 14109 Berlin, Germany
We report on studies on the CMR-compounds Y_xCa_1-xR_yMn_1-yO_3 which exhibit changing magnetic properties depending on concentration x and temperature. From the G-type AF CaMnO3, a new magnetic (C-type AF) phase occurs when exchanging Calcium by Yttrium in the region of x>=0.1. Phase transition temperature, phase fraction and strength of the magnetic moment of these phases depends strongly on the dopant R and amount y. Temperature dependent data collected with neutron and x-ray (powder) diffractometers has been analyzed simultaneously to determine the fractions of the different possible and realized magnetic and nuclear phases (nuclear structures P2_1/m, Pnma, magnetic structure type G,C,F,A).
For the substitution of Manganese by Gallium pronounced shifts in phase transition temperature are recorded, while the substitution by Iron leads to much weaker magnetic intensities with less effects on the nuclear structure.