Effect of spacer layer thickness on the magnetic and electrical properties of La/sub 0.7/Sr/sub 0.3/MnO/sub 3//SrTiO/sub 3/ superlattices

Summary form only given. Heteroepitaxial structures of colossal magnetoresistive manganites are of high interest for designing new devices with specific properties. SrTiO/sub 3/ has been found to be a promising interlayer in the fabrication of tunneling devices. This motivated us to study the effect of spacer layer thickness on the electrical and magnetic properties of La/sub 0.7/Sr/sub 0.3/MnO/sub 3/ (LSMO)/SrTiO/sub 3/ (STO) superlattices. The temperature dependence of magnetization showed a ferromagnetic transition for all studied films. However, the transition temperature did not show a monotonic dependence on d/sub STO/. The same behavior was observed for the saturation magnetization. The temperature dependence of electrical resistivity measurements showed metallic behavior below 300 K. Magnetoresistance measured at 20 K was found to depend on the d/sub STO/ and correlates with the magnetic measurements. The results are discussed in the light of surface corrugation due to epitaxial strain, the surface dead layer concept and interlayer coupling.