Structural, magnetic and electrical transport properties of V doped Bi0.3Ca0.7MnO3

Structural, magnetic, and transport properties of the compounds Bi0.3Ca0.7Mn1−xVxO3 with 0 ≤ x ≤ 0.1 have been experimentally investigated. This substitution introduces non-magnetic dopant V5+(3d04S0, S = 0) in the Mn-O-Mn network, which results in the variation of the Mn3+/Mn4+ ratio. It is suggested that Mn4+ ions are substituted by V5+ ions, which gives rise to the increase of Mn3+ ions. The electronic transport and magnetization results show that the temperature of charge ordering increases with increasing V-doping content. In addition, for all the samples, the temperature of resistivity in the temperature range above the charge ordering transition can be described by the adiabatic hopping of small polaron model, whereas below the charge ordering transition, Mott's variable range hopping mechanism is seen to be valid. The enhanced charge ordering caused by V-doping is suggested to originate from the enhanced Jahn-Teller distortion of the MnO6 octahedrons due to increased Mn3+ ions.