Strongly frustrated magnetism and colossal magnetoresistance in polycrystalline La0.47Ce0.20Ca0.33MnO3 -: art. no. 064424

We present x-ray diffraction, x-ray photoemission spectroscopy, magnetization, and transport results on the cerium-doped manganite La0.47Ce0.20Ca0.33MnO3. We have achieved good quality, single-phase polycrystalline samples by the nitrate decomposition route. A Rietveld analysis of the x-ray spectrum revealed a distorted structure with a small Mn-O-Mn apical angle of 152.6degrees. We found that both 3+ and 4+ charge states of cerium ions coexist, introducing an additional source of cation disorder in the A site of the perovskite structure. The low-temperature magnetization measurements, together with the high-T susceptibility results, indicate a magnetically frustrated behavior below T(F)approximate to70 K. The zero-field resistivity shows, at T(M)approximate to145 K, the typical metal-insulator transition found in manganite systems, though a temperature for a long-range ferromagnetic order transition does not obviously exist. The magnetoresistance (MR) is large, with a maximum value close to 100%. Strong hysteresis effects are observed in the MR vs field curves, that correlate well with the magnetization vs temperature measurements. We discuss these observations and show that the resistivity results are closely related to the magnetic behavior of the system.