| Popis: |
Dielectric characterization of multiferroics, using dielectric spectroscopy, answers the questions of electric dipole dynamics and their phase transitions. When probing the ordering of electric dipoles, dielectric spectroscopy may be somewhat restrictive in the sense that nonlinear effects are not readily recognized. Different methods are needed to obtain high-field properties of a particular phase in question. The Sawyer-Tower bridge is an experimental method that directly probes the static polarization of a sample [1]. In this work we will present a version of Sawyer-Tower bridge which we designed specifically to characterize of polarization of samples with low capacitances and in extreme conditions (low temperatures, high magnetic fields). We will demonstrate some of the physical quantities that can be extracted using this method as well as discuss issues we encountered during development. Finally, we will show preliminary polarization measurements on a one-dimensional quantum magnet β-TeVO4. [1] Stewart, M. ; Cain, M.G. Ferroelectric hysteresis measurement & analysis. InNPL Report CMMT(A) 152 ; National Physical Laboratory, University of Manchester: Manchester, UK, 1999 |
