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

Frequency-dependent capacitance measurements and transport measurements tun ed to reveal system impedance have been performed on epitaxial thin films o f Pr0.67Ca0.33MnO3. These reflect strong dielectric response features corre lated to the various ordering transition temperatures in the system, namely , similar to 220 K (charge ordering), similar to 130 K (antiferromagnetic o rdering), 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 t ransition. The enhanced dielectric response at the transitions is attribute d to the nonequilibrium transport and slow carder reorganization dynamics d efined by polaronic hopping and magnetic frustration.