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arXiv · 1311.0673

Large magnetocapacitance in electronic ferroelectric manganite systems

Ujjal Chowdhury·Sudipta Goswami·Dipten Bhattacharya·Arindam Midya·P. Mandal·P. Das·Y. M. Mukovskii
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Abstract

We have observed a sizable positive magnetocapacitance ($\sim$$5-90\%$) in perovskite Pr$_{0.55}$Ca$_{0.45}$MnO$_3$ and bilayer Pr(Sr$_{0.1}$Ca$_{0.9}$)$_2$Mn$_2$O$_7$ system under 5T magnetic field across 20-100 K below the magnetic transition point T$_N$. The magnetodielectric effect, on the other hand, exhibits a crossover: (a) from positive to negative for the perovskite system and (b) from negative to positive for the bilayer system over the same temperature range. The bilayer Pr(Sr$_{0.1}$Ca$_{0.9}$)$_2$Mn$_2$O$_7$ system exhibits a sizable anisotropy as well. We have also noticed the influence of magnetic field on the dielectric relaxation characteristics of these systems. These systems belong to a class of improper ferroelectrics and are expected to exhibit charge/orbital order driven ferroelectric polarization below the transition point T$_{CO}$. Large magnetocapacitance in these systems shows typical multiferroic behavior even though the ferroelectric polarization is small in comparison to that of other ferroelectrics.

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Ujjal Chowdhury, Sudipta Goswami, Dipten Bhattacharya, Arindam Midya, P. Mandal, P. Das, Y. M. Mukovskii. 2013-11-04. Large magnetocapacitance in electronic ferroelectric manganite systems. https://doi.org/10.1063/1.4831944

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