Dresden 2014 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 19: Poster I
MA 19.21: Poster
Dienstag, 1. April 2014, 13:00–15:30, P1
Capacitance and polarization of multiferroics at high magnetic fields — •Zhao-Sheng Wang, Joseph Law, Erik Kampert, Thomas Herrmannsdörfer, and Joachim Wosnitza — Hochfeld-Magnetlabor Dresden (HLD), Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany
We have investigated the multiferroic compound LiCuVO4 by means of capacitance and polarization measurements. For that purpose we have developed an experimental setup for capacitance and dielectric polarization measurements which can be operated in high pulsed magnetic field. The capacitance is measured using a high precision capacitance bridge (GR1615-A) which is balanced before the pulse. In order to avoid electrical noise arising from the magnetic-field pulse, we operate the capacitance bridge at frequencies above 10 kHz. The excitation signal and the voltage of the bridge circuit are recorded by a digital oscilloscope at a high sampling rate (1 MS/ s) and high resolution (16 bit). Signal postprocessing is performed by a computational lock-in procedure providing a resolution on the 10−15 F scale. Using that technique, we were able to demonstrate the occurence of a phase transition of LiCuVO4 in pulsed magnetic fields. In future, the experimental setup will be used for mapping out phase diagrams of further materials, such as multiferroics which exhibit phase transitions at very high magnetic fields).