Berlin 2008 – scientific programme

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MA: Fachverband Magnetismus

MA 16: Magnetic Particles and Clusters I

MA 16.8: Talk

Tuesday, February 26, 2008, 12:15–12:30, H 1028

Coexistence of superparamagnetism and optical activity in Ni_xPt_1−x/CdSe hybrid nanoparticles — •Ole Albrecht¹, Torben Menke¹, Jan Niehaus², Kirsten Ahrenstorf², Horst Weller², Kornelius Nielsch¹, and Detlef Görlitz¹ — ¹Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg — ²Institut für Physikalische Chemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg

NiPt-nanoparticles, the synthesis of which have been described previously together with their magnetical properties[1], where used as starting point for the synthesis of new complex hybrid nanoparticles. Covering Ni_xPt_1−x-particles with CdSe, an optically active semiconductor, a core-shell hybrid particle is formed featuring magnetic and, moreover, optical properties: the particles luminesce between 680 nm and 695 nm, detected by ensemble photoluminescence spectroscopy. The pure Ni_xPt_1−x-particles exhibit a superparamagnetic behavior with a blocking temperature T_b ≈ 4 K shown by SQUID-magnetometry. In the hybrid particles, T_b is shifted to lower temperatures. Possible reasons for this are discussed.

[1] K. Ahrenstorf et al., Small 3, 271(2007)