Phase transformations and magnetotransport properties of the Pr0.5Sr0.5Co1 − xMnxO3 system

  • I. O. Troyanchuk
  • A. N. Chobot
  • N. V. Tereshko
  • D. V. Karpinskii
  • V. Efimov
  • V. Sikolenko
  • P. Henry
Order, Disorder, and Phase Transition in Condensed System

DOI: 10.1134/S1063776111030162

Cite this article as:
Troyanchuk, I.O., Chobot, A.N., Tereshko, N.V. et al. J. Exp. Theor. Phys. (2011) 112: 837. doi:10.1134/S1063776111030162

Abstract

The structural, magnetic, and magnetotransport properties of Pr0.5Sr0.5Co1 − xMnxO3 (x < 0.65) perovskites are studied by magnetization and electrical conductivity measurements in magnetic fields up to 14 T and by neutron diffraction. In the manganese concentration range x < 0.5 and T = 300 K, the crystal structure is described by monoclinic space group I2/a; at x > 0.5, it is described by orthorhombic space group Imma. When the temperature decreases, a structural transformation without changing the symmetry takes place in all compounds. This transformation is caused by an active role of the inner shells of the praseodymium ion in chemical bond formation. The substitution of manganese for cobalt breaks a long-range ferromagnetic order near x ≈ 0.25, and a metal-dielectric transition occurs at x ≈ 0.15. The negative magnetoresistance is found to be maximal near a critical manganese concentration, where a long-range magnetic order is broken; it reaches 95% in a field of 14 T at T = 10 K for x = 0.2. An unusual dielectric magnetic state with a small spontaneous magnetic moment and a sharp transition into a paramagnetic state at T > 200 K is revealed in the concentration range 0.30 ≤ x ≤ 0.65 in spite of the absence of coherent magnetic neutron scattering. A model is proposed to explain the behavior of the magnetic properties in this phase.

Copyright information

© Pleiades Publishing, Ltd. 2011

Authors and Affiliations

  • I. O. Troyanchuk
    • 1
  • A. N. Chobot
    • 1
  • N. V. Tereshko
    • 1
  • D. V. Karpinskii
    • 1
  • V. Efimov
    • 2
  • V. Sikolenko
    • 3
  • P. Henry
    • 4
  1. 1.Scientific and Practical Materials Research CentreNational Academy of Sciences of BelarusMinskBelarus
  2. 2.Joint Institute for Nuclear ResearchDubna, Moscow oblastRussia
  3. 3.Paul Scherrer InstituteVilligen PSISwitzerland
  4. 4.Helmholtz Center BerlinBerlinGermany