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      https://www.ias.ac.in/article/fulltext/boms/039/04/1109-1117

    • Keywords

       

      Manganites; structural disorder; transport behaviour; phase segregation.

    • Abstract

       

      The results of the studies on structural disorder-induced modifications in the transport behaviour of La$_{0.5}$Pr$_{0.2}$Ca$_{0.3−x}$Ba$_x$MnO$_3$ (LPCBMO) ($0.05 ≤ x ≤ 0.30$) manganites were reported. Structural studies using X-ray diffraction (XRD) measurements confirmed the single phasic nature of all the samples without any detectable impurities. The A-site size disorder ($σ_2$ A) increased from $3.81 \times 10^{−5} (x = 0.05)$ to $14.9 \times 10−5 (x = 0.30)$. With the increase in structural disorder in LPCBMO system, the transport improved for the range: $0.15 ≤ x ≤ 0.30$, which can be ascribed to the enhancement in one electron bandwidth which dominates over the structural disorder effect, while for lower values of $x$, strong competition existed between size disorder and one electron bandwidth. Below 50 K, all $\rho–T$ plots showed resistivity minimum behaviour, which modified with disorder. This behaviour wasdiscussed in detail on the basis of electron–electron interaction having the form: $\rho = [1/(\rho_0 + BT^{1/2})] + \rho_nT_n$. Variation in temperature sensitivity with disorder was also discussed in context of granular morphology and phasesegregation scenario.

    • Author Affiliations

       

      ZALAK JOSHI1 D D PANDYA1 DAVIT DHRUV1 2 KEVAL GADANI1 HETAL BORICHA1 SANJAY KANSARA1 J H MARKNA2 P S SOLANKI1 N A SHAH1

      1. Department of Physics, Saurashtra University, Rajkot 360 005, India
      2. V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, India
    • Dates

       
  • Bulletin of Materials Science | News

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