Structural Magnetic and Electrical Properties in Nd-Doped Manganites (La sub(0.70-x )Nd sub( x ))Sr sub(0.30)Mn sub(0.70)Ti sub(0.30)O sub(3) with 0 less than or equal to x less than or equal to 0.30

• Published in: Journal of superconductivity and novel magnetism 2014-10, Vol.27 (10), p.2353-2364
• Main Authors: Abassi, Amel, Kallel, Nabil, Kallel, Sami, Pena, Octavio
• Format: Article
• Language: English
• Subjects: Competition; Electrical properties; Electrical resistivity; Ferromagnetism; Magnetic properties; Manganites; Neodymium; Phases
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-014-2597-x

The structural, magnetic and electrical properties of (La sub(0.70-x)Nd sub(x))Sr sub(0.30)Mn sub(0.70)Ti sub(0.30)O sub(3) perovskites (0 less than or equal to x less than or equal to 0.30) prepared by the usual ceramic procedure were investigated. Structural Rietveld refinements of the X-ray powder diffraction revealed that for x = 0 the compound crystallizes in a rhombohedral (R \(\bar {{3}}\) c) perovskite structure, while for x = 0.10, 0.20 and 0.30 the structure becomes orthorhombic (Pbnm). The field-cooled, zero-field-cooled and M(H) measurements lead to conclude that the samples with x greater than or equal to 0.10 behave like spin-glass systems. The temperature dependence of the resistivity exhibits two transitions at two temperatures T sub(p1) and T sub(p2), with the same width for the two peaks. T sub(P1) results from the competition between double-exchange and super-exchange mechanisms inside the grain (intrinsic effects) whereas T sub(P2) arises due to the grain boundary effects (extrinsic effect). The resistivity of this system seems to be related to the competition between antiferromagnetic insulating (AFI) phases, ferromagnetic insulating (FMI) phases and ferromagnetic metal (FMM) phases, which is induced by Nd doping effect.