Influence of cation mismatch on electrical, magnetic and magnetoresistance properties of Pr0.67A0.33MnO3manganites

✍ Scribed by Venkataiah, G. ;Venugopal Reddy, P.

• Book ID: 105363921
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 881 KB
• Volume: 204
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200622426

✦ Synopsis

Abstract

With a view to investigate the influence of A‐site cation mismatch on electrical, magnetic and magnetoresistance properties of Pr~0.67~A~0.33~MnO~3~, (A = Ca, Sr, Pb and Ba) manganites, a systematic investigation has been undertaken by preparing the materials using citrate gel route. The samples were characterized by X‐ray diffraction (XRD) and scanning electron microscopy. The XRD data were analyzed by Rietveld refinement method, while the crystallite sizes were estimated using the peak broadening technique. The unusual behavior of large magnetoresistance at low temperatures and at high magnetic fields has also been investigated. Finally, the high temperature electrical resistivity data were analyzed using variable range hopping and small polaron conduction mechanisms. A systematic investigation of the influence of average ionic radius of the A‐site (〈r~A~〉) and cation mismatch (σ^2^) on electrical and magnetic properties, viz., transition temperatures, density of states at Fermi level, polaron activation energies etc., has been undertaken. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)