Spin-glass behavior in (A,B)-site deficient manganese perovskites

  • Lee, Kyu-Won (Korea Research Institute of standards and Science) ;
  • Phan, Manh-Huong (Department of physics, Chungbuk National University) ;
  • Yu, Seong-Cho (Department of physics, Chungbuk National University) ;
  • Nguyen Chau (Center for Materials Science, National University of Hanoi) ;
  • Tho, Nguyen-Duc (Center for Materials Science, National University of Hanoi)
  • Published : 2003.06.01

Abstract

In the past years, a giant magnetoresistance (GMR) effect found in perovskite-like structured materials has attracted considerable attention among scientists and manufacturers, since, a practical point of view, the capacity of producing magnetic and sensing sensors. In a stream of this interest, further efforts to understand the underlying mechanism that leads to the GMR effect relative to the correlation between transport and magnetic properties, have been extensively devoted. In these cases, spin-glass-like behaviors are ascribed to the frustration of random competing exchange interactions, namely the ferromagnetic double-exchange interaction between Co$\^$3+/ (or Mn$\^$3+/) and Co$\^$4+/(or Mn$\^$4+/) and the antiferromagnetic one like spins. Noticeably, the distinction of spin-glass region from cluster-glass one, involved in the remarkable changes in transport and magnetic properties at a critical value of doping concentration, was observed. Magnetic anomalies in zero-field-cooled (ZFC) magnetization as well as ac magnetic susceptibility below Curie temperature T$\sub$c/ and the charge/orbital fluctuation were also realized. In this work, we present a study of magnetic properties of a deficient manganese perovskites system of La$\sub$0.6/Sr$\sub$x/MnTi$\sub$y/O$_3$, and particularly provide its new magnetic phase diagram.

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