Structure and electrical resistivity of La1−xBaxMnO3 (0.25 ≤ x ≤ 0.35) perovskites

The structural properties and resistivity of La1−xBaxMnO3 (0.25 ≤ x ≤ 0.35) manganites have been investigated. The Rietveld refinement of X-ray powder diffraction patterns fitted using the FullProf refinement program shows that these compounds having a cubic, and hexagonal structure with space group Pm3m, and R3¯c for La1−xBaxMnO3 (0.25 ≤ x ≤ 0.35). The temperature dependent resistivity curves undergo a metal–semiconductor transition (TMS) at ∼200 K (x = 0.25), ∼220 K (x = 0.30) and ∼230 K (x = 0.35) for La1−x BaxMnO3. The temperature dependence of resistivity shows a minimum behavior at low temperatures (T ≤ 50 K), explained by electron–electron and Kondo-like spin dependent scattering. The metallic resistivity is analyzed, to our knowledge, for the first time highlighting the importance of electron–phonon, electron–electron, and electron–spin fluctuation interactions. For T > TMI the semiconducting nature is discussed with small polaron conduction model.

► The structure of these compounds is cubic and hexagonal.
► The electrical resistivity of all the samples shows metal–semiconductor transition.
► The magnitude of resistivity is suppressed under the application of magnetic field.
► A resistivity upturn is observed at very low temperature region.
► The high temperature semiconducting resistivity data is analyzed by SPC model.