Temperature dependence of electron mobility in GaAs-Al(x)Ga (1-x)As heterostructures from 1 to 10K.

We report the temperature dependence of the channel resistance in three high mobility GaAs-Al(x)Ga(1-x) heterostructures between 1 and 10K. We find a positive correction with linear temperature dependence for the highest mobility sample and a negative sublinear correction for the lower mobility samples. The channel mobility of the highest mobility sample increases with density following mu~n(1.65), implying that impurity scattering is the dominant scattering mechanism.