Field-Induced Crossover and Colossal Magnetoresistance in   La(0.7)Pb(0.3)MnO(3)
  A field-induced crossover is observed in the resistivity and magnetization (M) of a La(0.7)Pb(0.3)MnO(3) single crystal. The field-dependence of the resistivity and M suggests that a small spin-canted species with mean-field-like interactions dominates at low fields (H), whereas, individual spins and 3D Ising/Heisenberg models describe the high-H behavior rather well. Around the ferromagnetic transition, an H-induced destruction of the small spin-canted magnetic polarons is accompanied by large magnetoresistance. 
Y. Y. Xue (1), B. Lorenz (1), A. K. Heilman (1), M. Gospodinov (2), S.   G. Dobreva (2) and C. W. Chu (1,3) ((1) Texas Cente...