High dielectric constant in charge-ordered Ca1.75Pr0.25MnO4

We report the dielectric response of Ca2-xPrxMnO4 (x = 0 and 0.25). Specifically, their intrinsic dielectric constants (epsilon(')(r)) are calculated by impedance spectroscopy from the values of the obtained bulk capacitances. For Ca2MnO4, that does not show charge-order, the measured intrinsic dielectric constant is 14. The Pr doping induces charge-order in the system, and also a noteworthy increase in epsilon(')(r), that reaches a value of similar to 220 for x = 0.25, unusual in these kind of oxides. This result provides a new link between both phenomena.