Influence of doping level on the Hall coefficient and on the   thermoelectric power in $Nd_{2-x}Ce_xCuO_4$
  Hall coefficient $R_H$ and thermoelectric power TEP are studied systematically in the single crystals $Nd_{2-x}Ce_xCuO_{4+\delta}$ (NCCO) with different x from underdoped to overdoped regime. With increasing doping level, both $R_H$ and TEP decrease and change their sign from negative to positive. A striking feature is that the temperature dependence of the Hall angle follows a $T^4$ behavior in the underdoped regime, while a $T^2$ in the overdoped regime. These behaviors are closely related to the evolution of Fermi surface with doping level observed by ARPES. 
C. H. Wang, G. Y. Wang, T. Wu, Z. Feng, X. G. Luo, X. H. Chen