Berlin 2005 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Magnetismus
MA 29: Magnetische Materialien
MA 29.4: Vortrag
Dienstag, 8. März 2005, 16:00–16:15, TU A060
Doped semi-conductors as HMF materials: CoTi1−xFexSb — •Kristian Kroth, Gerhard H. Fecher, Vadim Ksenofontov, Claudia Felser, and Gerd Schönhense — Johannes Gutenberg - Universität, 55099 Mainz, Germany
CoTiSb is known to be a semiconducting half Heusler compound. Doping by Fe is expected to result in ferromagnetic order. It was found that Ti can be replaced by up to 5% Fe while its crystal structure still remains C1b, which was proved by X-ray powder diffraction and Mößbauer spectroscopy. SQUID magnetometry revealed a magnetic moment of 0.2µB per formula unit. SCF calculations using the KKR-CPA method predict a half metallic ferromagnetic character with only Fe atoms contributing to the total magnetization of the alloy. This is in agreement to experiments using XMCD at L2,3 edges to determine the atomic resolved contribution of the 3d metals to the magnetic moment.
An alternative way of synthesis, besides arc-melting of the four components, had been tried out by Fe ion implantation into an arc-melted CoTiSb sample. Surface investigations of such samples were carried out by XAS-PEEM and Nano-ESCA devices in order to examine the spatial distribution of the elements.