The resistivity tensors of La0.67Ca0.33MnO3 films were investigated at temp
eratures from the Curie temperature up to 600 K in magnetic fields up to 20
T. The diagonal transport is described by hopping of a small spin polaron
cluster of 4 ions to nearest-neighbor spins. A spin-dependent activation en
ergy and a mean field approximation for the magnetization of clustered pola
ron spins and unclustered Mn ion spins allowed the description of rho(B, T)
with a minimum of free parameters. The electron-like low field Hall coeffi
cient showed a thermally activated behavior with an activation energy highe
r than that extracted from diagonal data. (C) 1999 American Institute of Ph
ysics. [S0021-8979(99)19408-8].