Eur. Phys. J. B 49, 37-45 (2006)
https://doi.org/10.1140/epjb/e2006-00027-y

Anomalous magnetoresistance in [Sr₂Bi_2-xPb_xO₄]^RS[CoO₂]_y (x = 0, 0.3, and 0.4; y ≈ 1.85) single crystals

Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China

Corresponding author: ^a chenxh@ustc.edu.cn

Received: 15 September 2005
Published online: 31 January 2006

Abstract

Magnetoresistance (MR) of the [ Sr₂Bi_2-xPb_xO₄]^RS[ CoO₂] _y (x = 0, 0.3, and 0.4; y ≈ 1.85; RS is referred to rocksalt block) single crystals is investigated systematically. A nonmonotonic variation of the isothermal in-plane and out-of-plane MR with the field is observed. The out-of-plane MR is positive at high temperatures and increases with decreasing T, and exhibits a pronounced hump, then changes the sign from positive to negative at a certain temperature. These results strongly suggest that the observed MR consists of two contributions: one negative and one positive component. The isothermal MR in high magnetic fields follows a H² law. The negative contribution comes from spin scattering of carriers by localized-magnetic-moments based on the Khosla-Fischer model.