Hall effect and conductivity in La1−xBaxMnO3 single crystals

Abstract We study the transport properties of La1−xBaxMnO3 ( x = 0.1 5 , 0.20, and 0.28) single crystals grown by the floating zone method. The magnetization, Hall effect, and resistivity ρ were measured in temperature range of 77–400 K in magnetic fields up to 15 kOe. It is shown that the band structure of the colossal magnetoresistance (CMR) manganites is determined by not only doping level but also the type of divalent ions. Near the Curie temperature TC, in all the samples ln ρ is linear in squared magnetization, which indicates the conductivity of semiconductor type with activation energy determined by the interaction with localized spins; the metal–insulator transition, if any, occurs below TC.