title: Interplay between the crystalline and magnetic structures in lightly Cr-doped Bi(0.37)Ca(0.63)Mn(0.96)Cr(0.04)O(2.99).
abstract: The interplay between the crystalline and magnetic structures of a 4% Cr-doped Bi(0.37)Ca(0.63)Mn(0.96)Cr(0.04)O(2.99) has been investigated by alternating current (ac) magnetic susceptibility, electrical resistivity, and neutron diffraction measurements. The compound crystallizes into a monoclinic P2(1)/m symmetry. A Jahn-Teller distortion occurs at 280 K. The thermal behavior of charge transport may be described by a three-dimensional variable range hopping conduction. Strong interplay between the localized magnetic electrons and the itinerant electrons are clearly revealed as the localization length increases by 20% when the Mn spins become ordered below 85 K. Short range magnetic correlations persist up to 160 K. The collinear magnetic structure can be viewed as consisting of ferromagnetic spin-trimers antiferromagnetically embedded in a ferromagnetic environment. Cr-doping reduces the charge ordering temperature and the magnetic ordering temperature. It nevertheless introduces long-range ferromagnetism.
authors.affiliation: Department of Physics, Chung-Yuan Christian University, Jhongli, 32023 Taiwan.
authors.forename: Chun-Chuen
authors.initials: CC
authors.lastname: Yang
authors.forename: Wen-Hsien
authors.initials: WH
authors.lastname: Li
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Wu
authors.forename: Carissa H C
authors.initials: CH
authors.lastname: Li
authors.forename: Jirong
authors.initials: J
authors.lastname: Sun
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Lynn