T_C Suppression of SrRuO₃/SrTiO₃ Superlattices

Abstract

The transverse and longitudinal magnetoresistivities of SrRuO₃/SrTiO₃ superlattices on SrTiO₃ (001) substrates were measured to study low-dimensional effects on the magnetic properties of SrRuO₃. Both the differential resistivity, dρ (T)/dT, and magnetoresistivity, {Δ}ρ (H)=ρ (H)-ρ (0), become maximum at the ferromagnetic transition temperature, T_C. The transition appears when the SrRuO₃ layer is as thick as 2 unit-cells or more. The T_C decreases quickly with decreasing thickness, especially for less than 4 unit-cell thickness.