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La0.60Sr0.40MnO3 (LSMO) thin films of varying thickness from 12 to 55 nm were deposited using the pulsed-laser deposition technique onto single-crystalline SrTiO3 (STO) and STO-buffered Si substrates. The Tc of LSMO films grown on STO-buffered Si substrates decreases faster than films directly grown on STO with decreasing film thickness. The LSMO/STO film with thickness of 55 nm shows Tc at about 360 K, which is close to the bulk value, whereas Tc LSMO film on STO-buffered Si film of similar thickness is reduced to 320 K. This difference is attributed to the strain and interfacial disorders in LSMO film on STO/Si. The film surface morphology is influenced by the film thickness. Oxygenation of LSMO films on STO-buffered Si affects the Tc minimally but improved the overall magnetization of the films due to better oxygenation, which is also the case for postannealing the sample at elevated temperatures. The thermomagnetic history effects observed in LSMO films of STO-buffered Si indicate the presence of inhomogeneity, mostly at the interface, which influences the magnetic properties significantly. [ABSTRACT FROM AUTHOR]

We report on the fabrication and tunneling characteristics of pulsed-laser deposited LaSrMnO (LSMO)/PbZrTiO(PZT)/LSMO/SrTiO3 multilayers, using PZT layer as a tunnel barrier. The trilayer films show magnetic onset at about 360 K with ferromagnetic hysteresis at room temperature. The microscopic studies show that the effective barrier thickness is reduced due to the presence of defects in the barrier region. Our results suggest that the asymmetric deformation of the barrier potential profile induced by the ferroelectric polarization of PZT influences the tunneling characteristics and can be used for electrically controlled readout in quantum-computing schemes. [ABSTRACT FROM AUTHOR]