Electric and magnetic properties of Lanthanum Barium Cobaltite

"This is the peer reviewed version of the following article: Szpunar, Iga, Sebastian Lech Wachowski, Tadeusz Miruszewski, Kacper Dzierzgowski, Karolina Górnicka, Tomasz Klimczuk, Magnus H. Sorby, Maria Balaguer, José M Serra, Ragnar Strandbakke, Aleksandra Dorota Mielewczyk-Gry¿, and Maria Gazda. ¿Electric and Magnetic Properties of Lanthanum Barium Cobaltite¿. JOURNAL OF THE AMERICAN CERAMIC SOCIETY 103 (2020): 1809-18. https://doi.org/10.1111/jace.16865, which has been published in final form at https://doi.org/10.1111/jace.16865. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The cubic Ba0.5La0.5CoO3-delta was synthesized using solid state reaction. The structural properties were determined by the simultaneous refinement of Synchrotron Powder X-ray Diffraction and Neutron Powder Diffraction data. Iodometric titration was used to examine the oxygen stoichiometry and average cobalt oxidation state. Low-temperature magnetic studies show soft ferromagnetic character of fully oxidized material, with theta(P) = 198(3) K and mu(eff) = 2.11(2) mu(B). Electric measurements show the thermally activated nature of conductivity at low temperatures, whereas, due to the variable oxidation and spin state of cobalt, a single charge transport mechanism cannot be distinguished. Around room temperature, a wide transition from thermally activated conductivity to semi-metallic behavior is observed. Under the inert atmosphere, the oxygen content lowers and the cation ordering takes place, leading to coexistence of two, ordered and disordered, phases. As a result of this change, thermally activated conductivity is observed also at high temperatures in inert atmosphere.The authors acknowledge the skillful assistance from the staff of the Swiss-Norwegian Beamline (SNBL), at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The research has been supported by the National Science Centre Poland under m.ERA.net funding scheme (2016/22/Z/ST5/00691). Funding from the Spanish Government (PCIN-2017-125, RTI2018-102161) is kindly acknowledged. Financial and scientific contributions from the Research Council of Norway (Grant no 272797 "GoPHy MiCO") through the M-ERA.NET Joint Call 2016.Szpunar, I.; Wachowski, S.; Miruszewski, T.; Dzierzgowski, K.; Gornicka, K.; Klimczuk, T.; Sorby, M.... (2020). Electric and magnetic properties of Lanthanum Barium Cobaltite. Journal of the American Ceramic Society. 103(3):1809-1818. https://doi.org/10.1111/jace.16865180918181033Ivanova, N. B., Ovchinnikov, S. G., Korshunov, M. M., Eremin, I. M., & Kazak, N. V. (2009). Specific features of spin, charge, and orbital ordering in cobaltites. Physics-Uspekhi, 52(8), 789-810. doi:10.3367/ufne.0179.200908b.0837Nakajima, T., Ichihara, M., & Ueda, Y. (2005). New A-site Ordered Perovskite Cobaltite LaBaCo2O6: Synthesis, Structure, Physical Property and Cation Order–Disorder Effect. Journal of the Physical Society of Japan, 74(5), 1572-1577. doi:10.1143/jpsj.74.1572Strandbakke, R., Cherepanov, V. A., Zuev, A. Y., Tsvetkov, D. S., Argirusis, C., Sourkouni, G., … Norby, T. (2015). Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells. Solid State Ionics, 278, 120-132. doi:10.1016/j.ssi.2015.05.014Frontera, C., Caneiro, A., Carrillo, A. E., Oró-Solé, J., & García-Muñoz, J. L. (2005). Tailoring Oxygen Content on PrBaCo2O5+δ Layered Cobaltites. Chemistry of Materials, 17(22), 5439-5445. doi:10.1021/cm051148qFauth, F., Suard, E., Caignaert, V., Domengès, B., Mirebeau, I., & Keller, L. (2001). Interplay of structural, magnetic and transport properties in thelayered Co-based perovskite LnBaCo 2 O 5 (Ln = Tb, Dy, Ho). The European Physical Journal B, 21(2), 163-174. doi:10.1007/pl00011119Luo, W., & Wang, F. (2006). Powder X-ray diffraction and Rietveld analysis of La1−xBaxCoO3 (0