Three-dimensional strain state and spacer thickness-dependent properties of epitaxial Pr0.7Sr0.3MnO3/La0.5Ca0.5MnO3/Pr0.7Sr0.3MnO3 trilayer structure

Epitaxial colossal magnetoresistive trilayer structures consisting of ferromagnetic metallic Pr0.7Sr0.3MnO3 (PSMO) and antiferromagnetic insulator La0.5Ca0.5MnO3 (LCMO) were fabricated on (001)-oriented single crystal MgO substrates using pulsed laser deposition technique. The evolution of three-dimensional strain states and electrical and magnetic transport properties of PSMO/LCMO/PSMO trilayers have been studied as a function of LCMO spacer thickness and lattice strain. When the thickness of LCMO spacer is 6 nm, lattice strain in the trilayer begins to be relaxed. Furthermore, trilayers with thickness of LCMO spacer up to 36 nm are not fully strain relaxation. The unit cell volume of the films is not conserved and exhibits the variation with LCMO layer thickness. Strain relaxation states are determined by bulk strain (epsilon(B)) and Jahn-Teller (epsilon(JT)) strain together. The electrical and magnetic transport properties, including metal-insulator transition temperatures T-MI and saturation magnetization M-S, also show systematic variations with respect to LCMO layer thickness. (C) 2014 AIP Publishing LLC.