| Abstract
| - La1-xNaxMnO3+δ samples with well-defined cation molecularity and oxygen contents (x = 0.05, x = 0.13,and −0.04 ≤ δ ≤ 0.078) are analyzed with XRPD, electrical conductivity, static magnetization, and EPRmeasurements. The majority defects induced by oxygen over- and under-stoichiometry are cation and oxygenvacancies; the cation vacancies affect the magnetic properties by interrupting the interaction paths betweenMn(III) and Mn(IV) ions, whereas the oxygen vacancies have a stronger influence on the structural andelectrical properties and act on the magnetic properties by the overall decrease of the Mn(IV) amount and bythe creation of sample regions with different magnetic features. We can state that the basic magnetic andelectrical behaviors of the Na-doped lanthanum manganite compounds are driven from the Mn(IV)/Mn(III)ratio and all the peculiar behaviors are indeed caused by defects, concentration gradient and, more generally,by lattice disorder.
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