Evidence of charge-carrier compensation effects in La0.67Ca0.33MnO3

We report on detailed Hall-effect measurements of thin films of La0.67Ca0.33MnO3 above and below the metal-insulator transition. In the metallic ferromagnetic regime, we find a temperature-independent holelike nominal charge-carrier density n(h)*=1.3 per unit cell, consistent with a partly compensated Fermi surface. The mobility is only 92 mm(2)/V s at 4 K, and decreases with increasing temperature. Huge negative magnetoresistivity results from an increase in mobility. In low magnetic fields or at high temperatures, an anomalous electronlike contribution dominates the Hall voltage. For possible side jumps, we estimate an average jump length of the electron wave packet of 10(-13) m. [S0163-1829(98)06919-7].