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KR: Fachgruppe Kristallographie

KR 5: Poster Multiferroics (Joint Session of MA, DF, DS, KR, TT)

KR 5.53: Poster

Dienstag, 15. März 2011, 10:45–13:00, P2

Magnetic Resonance and Magnetization Measurements of Multiferroic Eu_xBa_1−xTiO₃ — •Nataliya Georgieva¹, Andreas Pöppl¹, Rolf Böttcher¹, Marko Bertmer¹, Jürgen Haase¹, and Alex Sushkov² — ¹Faculty of Physics and Earth Sciences, University of Leipzig, Germany — ²Department, Yale University, New Haven, Connecticut, USA

We are investigating multiferroic Eu_xBa_1−xTiO₃ with different Eu²⁺ concentrations (x = 1, 0.75, 0.5, 0.25) using magnetic resonance spectroscopy (EPR and NMR) and magnetization measurements.

The ceramics samples exhibit different magnetic and electric properties depending on their Eu²⁺ concentration. SQUID magnetization measurements have revealed Curie-Weiss behavior of all samples and magnetic ordering at low temperatures.

The X- and Q-band EPR spectra show strongly dipole-broadened and exchange-coupled Eu²⁺ signals. Temperature dependent line broadening effects are observed and differ for various Eu²⁺ concentrations.

Preliminary ¹³⁷Ba NMR spectra were recorded using frequency stepped Hahn Echo experiments. The line width of the central ¹³⁷Ba nuclear quadrupole transition shows a striking dependence on the Eu²⁺ concentration.