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Electric and magnetic properties of lanthanum barium cobaltite
Author(s) -
Szpunar Iga,
Wachowski Sebastian,
Miruszewski Tadeusz,
Dzierzgowski Kacper,
Górnicka Karolina,
Klimczuk Tomasz,
Sørby Magnus Helgerud,
Balaguer María,
Serra José M.,
Strandbakke Ragnar,
Gazda Maria,
MielewczykGryń Aleksandra
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.16865
Subject(s) - cobaltite , cobalt , materials science , electrical resistivity and conductivity , barium , powder diffraction , lanthanum , neutron diffraction , iodometry , analytical chemistry (journal) , conductivity , reducing atmosphere , inert gas , oxidation state , barium oxide , stoichiometry , oxide , inorganic chemistry , chemistry , metal , crystallography , metallurgy , crystal structure , chromatography , electrical engineering , engineering , composite material
The cubic Ba 0.5 La 0.5 CoO 3‐δ 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 θ P = 198(3) K and µ eff = 2.11(2) µ 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.