Giant Magnetoresistance in Narrow-Gap Ferroelectric-Semiconductor PbSnTe:In

A giant (up to 10 4 ) magnetoresistance effect in magnetic fields B ≈ 4 T was observed in MBE-grown PbSnTe:In films under conditions with space-charge-controlled limitation of injection currents. The relative change in the electric current depended on the strength and mutual orientation of the two (electric and magnetic) fields. The effect is discussed in terms of a model in which the static dielectric permittivity e of the material is assumed to be dependent on crystallographic orientation. Experimental data that show how the permittivity e of PbSnTe:In films and their current-voltage characteristics depend on the orientation of the electric field vector at B = 0 are reported.