Determining Curie temperature of (Ga,Mn)As samples based on electrical   transport measurements: low Curie temperature case
  In this paper we show that the widely accepted method of the determination of Curie temperature (TC) in (Ga,Mn)As samples, based on the position of the peak in the temperature derivative of the resistivity,completely fails in the case of non-metallic and low-TC unannealed samples. In this case we propose an alternative method, also based on electric transport measurements, which exploits temperature dependence of the second derivative of the resistivity upon magnetic field. 
Adam Kwiatkowski, Marta Gryglas-Borysiewicz, Piotr Juszynski, Jacek   Przybytek, Maciej Sawicki, Janusz Sadowski, Dariusz Wa...
cond-mat.mtrl-sci