Electrical transport of SrRuO3 and La0.35Pr0.25Ca0.4MnO3 heterostructure grown by magnetron sputtering.

We report the structure and electrical transport of SrRuO₃ (SRO) and La_0.35Pr_0.25Ca_0.4MnO₃ (LPCMO) thin films and SRO/LPCMO bilayers grown on (001) oriented LaAlO₃ (LAO) substrates. The thin films and heterostructures were deposited by RF magnetron sputtering of SRO and LPCMO targets in 25 mtorr Ar+O₂ ambient at 850°C. The thickness of the SRO, LPCMO, and the bilayer is estimated to be ~3 nm, 40 nm, and 43 nm, respectively. The HRXRD 2θ-ω scans reveal that these films are (i) single crystalline, (ii) oriented along out-of-plane c-direction, and (iii) under slight compressive strain. The SRO film undergoes metal-semiconductor transition at T_MS ~160 K. In contrast, the LPCMO undergoes a first-order hysteretic insulator-metal transition (IMT) at T_IM ~154 K and 174 K during cooling and warming cycles. In the bilayer, the IMT of LPCMO is shifted to ~170 K and ~182 K during the cooling and warming cycle, with the insulating state concomitantly transformed into a semiconducting one. [ABSTRACT FROM AUTHOR]