Characterization and transport measurements of bulk and surface conduction of La and Eu doped SmB₆ using multi-terminal Corbino devices

Transport properties of topological Kondo insulator SmB₆ can be altered by either introducing vacancies or substitutional atoms such as La or Eu in the Sm site. In the case of samples with vacancies, we found the activated behavior at low temperatures to be independent of vacancy concentrations whereas we have observed differences in the high-temperature Hall coefficients. In this study, we have extended our transport experiments to samples with magnetic and non-magnetic doping. In the heavily doped samples such as Sm_0.6La_0.4B₆, both the bulk and surface transport measurements were polluted by the presence of cracks. We, therefore, focused on the dilute doping limit and found introduction as little as 3% of La can alter the magnitude of the Hall resistance at all temperatures including the sign at low temperatures. In addition to Hall measurements, we will present transport results from multi-terminal Corbino devices including inverted resistance measurements.