Correlation of large dielectric response with the ordering transitions in Pr0.67Ca0.33MnO3

Frequency-dependent capacitance measurements and transport measurements tuned to reveal system impedance have been performed on epitaxial thin films of Pr0.67Ca0.33MnO3. These reflect strong dielectric response features correlated to the various ordering transition temperatures in the system, namely, similar to 220 K (charge ordering), similar to 130 K (antiferromagnetic ordering), and similar to 117 K (spin canting). An equally strong feature is also seen at similar to 125 K, which does not correspond to any reported transition. The enhanced dielectric response at the transitions is attributed to the nonequilibrium transport and slow carder reorganization dynamics defined by polaronic hopping and magnetic frustration.