Abstract
Powder samples of ABO3 perovskite manganites with the composition Pr0.6Sr0.4MxMn1-xO3 (M=Fe, Co, or Ni, 0.00≤x≤0.25) were synthesized using the sol-gel method. X-ray diffraction analyses showed that all three sets of samples had a single phase with an orthorhombic structure. The magnetic moment, μobs, of the samples at 10 K, decreased slowly for x≤0.10, whereas μobs decreased rapidly for x≥0.10. The dependences of μobs on the doping level x for the three series of samples were fitted successfully. In the fitting process, Mn, Fe, Co, and Ni cations were assumed to be trivalent, and the magnetic moment directions of Fe3+, Co3+, and Ni3+ cations were assumed to be canted antiferromagnetically coupled with Mn3+ cations. The cant angle ϕ decreased with the increase in x for x≤0.10 for Fe- and Ni-doped (x≤0.15 for Co-doped) samples and increased rapidly when x≥0.10 (x≥0.15 for Co-doped) samples. These properties are discussed using an oxygen 2p itinerant electron model, which is very similar to the oxygen 2p hole model proposed by Alexandrov et al. [Phys. Rev. Lett. 96, 117003 (2006)].
Highlights
INTRODUCTIONOver the past thirty years, ABO3 perovskite manganites of the composition Ln1-xT xMnO3 (where Ln is a trivalent rare-earth element and T is a divalent alkaline-earth element) have been extensively studied in view of the observed colossal magnetoresistance (MR) of these compounds and their potential application in magnetic materials.[1,2,3,4,5,6,7,8,9,10,11]
Over the past thirty years, ABO3 perovskite manganites of the composition Ln1-xT xMnO3 have been extensively studied in view of the observed colossal magnetoresistance (MR) of these compounds and their potential application in magnetic materials.[1,2,3,4,5,6,7,8,9,10,11]There have been many studies on the substitution of various metallic elements for manganese in perovskite manganites owing to the significant changes in magnetic and transport properties resulting from such substitutions
Sun et al.[12] studied the magnetic and MR properties of La0.67Sr0.33CrxMn1-xO3 and observed that Cr substituted for Mn can result in a ferromagnetic interaction between Mn and Cr, similar to a double exchange
Summary
Over the past thirty years, ABO3 perovskite manganites of the composition Ln1-xT xMnO3 (where Ln is a trivalent rare-earth element and T is a divalent alkaline-earth element) have been extensively studied in view of the observed colossal magnetoresistance (MR) of these compounds and their potential application in magnetic materials.[1,2,3,4,5,6,7,8,9,10,11]. Chen et al.[16] prepared La0.7Sr0.3Mn1xCoxO3 (0.0≤x≤1.0) and observed that the magnetization decreased and reached a minimum at x=0.7 They considered that the double exchange interaction in La0.7Sr0.3MnO3 is destroyed by Co doping. In order to explain the magnetic and electrical transport properties of these systems, it is very important to understand the nature of the ferromagnetic or antiferromagnetic coupling in these materials using a uniform mechanism. Combined with our previous work on Cr-doped samples,[19] we discuss the magnetic and electrical transport properties using an O2p itinerant electron model, which is similar to the O2p hole model used to explain the electrical transport in ferromagnetic manganites.[20,21,22,23].
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