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We report the detailed study of dielectric response of Pr(0.6)Ca(0.4)MnO(3) (PCMO), member of manganite family showing colossal magnetoresistance. Measurements have been performed on four polycrystalline samples and four single crystals, allowing us to compare and extract the essence of dielectric response in the material. High frequency dielectric function is found to be 30, as expected for the perovskite material. Dielectric relaxation is found in frequency window of 20Hz-1MHz at temperatures of 50-200K that yields to colossal low-frequency dielectric function, i.e. static dielectric constant. Static dielectric constant is always colossal, but varies considerably in different samples from 1000 until 100000. The measured data can be simulated very well by blocking (surface barrier) capacitance in series with sample resistance. This indicates that the large dielectric constant in PCMO arises from the Schottky barriers at electrical contacts. Measurements in magnetic field and with d.c. bias support this interpretation. Weak anomaly at the charge ordering temperature can also be attributed to interplay of sample and contact resistance. We comment our results in the framework of related studies by other groups.
We report on DC and pulsed electric field sensitivity of the resistance of mixed valent Mn oxide based La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.4) single crystals as a function of temperature. The low temperature regime of the resistivity is highly current
We present resonant soft X-ray scattering (RSXS) results from small band width manganites (Pr,Ca)MnO$_3$, which show that the CE-type spin ordering (SO) at the phase boundary is stabilized only below the canted antiferromagnetic transition temperatur
We studied the charge-orbital ordering in the superlattice of charge-ordered insulating Pr$_{0.5}$Ca$_{0.5}$MnO$_3$ and ferromagnetic metallic La$_{0.5}$Sr$_{0.5}$MnO$_3$ by resonant soft x-ray diffraction. A temperature-dependent incommensurability
Thin films of strongly-correlated electron materials (SCEM) are often grown epitaxially on planar substrates and typically have anisotropic properties that are usually not captured by edge-mounted four-terminal electrical measurements, which are prim
We report the characterization of the crystal structure, low-temperature charge and orbital ordering, transport, and magnetization of Pr_{0.6}Ca_{0.4}MnO_{3} films grown on LaAlO_{3}, NdGaO_{3}, and SrTiO_{3} substrates, which provide compressive (La