Misfit dislocation arrays at the interface between La_0.9Sr_0.1MnO₃films and vicinal SrTiO₃(001) substrates

Abstract

The microstructural characteristics of misfit dislocations at the interface between La 0.9 Sr 0.1 MnO 3 films and vicinal SrTiO 3 substrates have been studied by transmission electron microscopy. The misfit dislocations were determined to be edge type with Burgers vector ah100i: Owing to the inclination of the substrate, the dislocation line along the miscut direction of the substrate is rotated. The deviation angle of the dislocation line away from the miscut direction of the substrate varies with the miscut angle. As a result, the dislocation arrays at the interface form a parallelogram dislocation network rather than an orthogonal network. A simple explanation of the misfit dislocation reaction with the step for the film on a vicinal substrate is proposed to interpret the rotation of the dislocation line along the miscut direction.

Epitaxial ferroelectric interfacial devices

“…550,551 The steps tend also to act as nucleation sites for film growth and can lead to a step flow growth mode and to atomically smooth surfaces; 552 however, the regions where the steps meet are sites susceptible to the formation of lattice defects, such as strain induced by residual lattice matching between the film and substrate, 553 stacking faults, 551 and vertical lattice mismatch as a result of step bunching; 554 additionally, the atomic steps interact with dislocations and modify their configuration in the film. 555 Defect chemistry also plays an important role at the growth temperature. Intrinsic defects, such as vacant sites (vacancies), atoms occupying interstitial sites (interstitials),…”

Interface structure governed by plastic and structural dissimilarity in perovskite La0.7Sr0.3MnO3 nanodots on rock-salt MgO substrates

“…3(b)). [14][15][16] Noticing that 1 = 2 h011i{011} is the most prominent glide system in the rock-salt structure, 17 and that LSMO is stiffer than MgO, 18,19 a likely mechanism to explain our observations is that 1 = 2 h011i dislocations are inherited from the substrate, as often observed in semiconductor heterostructures. 20 Accordingly, dislocations would reach the interface by gliding on MgO {011} planes intersecting the interface at 45 .…”