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Revealing strain effects on the chemical composition of perovskite oxide thin films surface, bulk, and interfaces

DOI: 10.1002/admi.201901440 DOI Help

Authors: Celeste A. M. Van Den Bosch (Imperial College, London) , Andrea Cavallaro (Imperial College, London) , Roberto Moreno (ICN2, Institut Catalá de Nanociéncia i Nanotecnologia) , Giannantonio Cibin (Diamond Light Source) , Gwilherm Kerherve (Imperial College, London) , José M. Caicedo (ICN2, Institut Catalá de Nanociéncia i Nanotecnologia) , Thomas K. Lippert (Paul Scherrer Institute) , Max Doebeli (ETH Zurich) , José Santiso (ICN2, Institut Catalá de Nanociéncia i Nanotecnologia; CSIC, Consejo Superior de Investigaciones Científicas) , Stephen J. Skinner (Imperial College, London) , Ainara Aguadero (Imperial College, London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Advanced Materials Interfaces , VOL 247

State: Published (Approved)
Published: December 2019
Diamond Proposal Number(s): 13530 , 16839

Abstract: Understanding the effects of lattice strain on oxygen surface and diffusion kinetics in oxides is a controversial subject that is critical for developing efficient energy storage and conversion materials. In this work, high‐quality epitaxial thin films of the model perovskite La0.5Sr0.5Mn0.5Co0.5O3−δ (LSMC), under compressive or tensile strain, are characterized with a combination of in situ and ex situ bulk and surface‐sensitive techniques. The results demonstrate a nonlinear correlation of mechanical and chemical properties as a function of the operation conditions. It is observed that the effect of strain on reducibility is dependent on the “effective strain” induced on the chemical bonds. In‐plain strain, and in particular the relative BO length bond, is the key factor controlling which of the B‐site cation can be reduced preferentially. Furthermore, the need to use a set of complimentary techniques to isolate different chemically induced strain effects is proven. With this, it is confirmed that tensile strain favors the stabilization of a more reduced lattice, accompanied by greater segregation of strontium secondary phases and a decrease of oxygen exchange kinetics on LSMC thin films.

Journal Keywords: chemical expansion; epitaxial thin films; in situ; interfaces; strain engineering

Subject Areas: Chemistry, Materials


Instruments: B18-Core EXAFS