1. Electric and magnetic properties of Lanthanum Barium Cobaltite
- Author
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Ragnar Strandbakke, Aleksandra Mielewczyk-Gryń, Maria Gazda, José M. Serra, María Balaguer, Tadeusz Miruszewski, Iga Szpunar, Sebastian Wachowski, Kacper Dzierzgowski, Magnus H. Sørby, Karolina Górnicka, and Tomasz Klimczuk
- Subjects
010302 applied physics ,Materials science ,Properties ,Analytical chemistry ,chemistry.chemical_element ,Barium ,02 engineering and technology ,Conductivity ,021001 nanoscience & nanotechnology ,01 natural sciences ,Cobaltite ,chemistry.chemical_compound ,chemistry ,Ferromagnetism ,Oxidation state ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Lanthanum ,Electrical properties ,Perovskites ,0210 nano-technology ,Inert gas ,Magnetic materials ,Cobalt - Abstract
[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.
- Published
- 2020