The problem with R(T) measurements is that you can't decouple the carrier density from the mobility; to do that you need to combine resistivity measurements with Hall measurements. Conveniently, the Van der Pauw geometry allows you to do both measurements on the same sample. Have a look on this discussion - the attached file is very clear and useful.

https://www.researchgate.net/post/How_are_carrier_concentration_and_mobility_obtained_from_a_Van_der_Pauw_experiment?_sg=wWTn0T3OJbz00iMCfPmKO3mKusU5J%2BvE%2BCAzh4KfYPIYaWsSzT3e7yAuWUuGSSMJ

You can do a Time of Flight measurement, called a Haynes experiment, to measure mobility independently. 

You can not measure the charge carrier mobility with the help of R-T measurement for that u need Hall measurement.