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O: Fachverband Oberflächenphysik
O 35: Poster Session - Tribology: Surfaces and Nanostructures
O 35.1: Poster
Montag, 16. März 2020, 18:15–20:00, P1C
Temperature dependent friction measurements of manganite films — •Niklas Weber, Hendrik Schmidt, Richard Vink, and Cynthia A. Volkert — Institute of Materials Physics, University of Göttingen, Germany
In this project, we use lateral force microscopy to investigate how friction of manganite films can be controlled by the properties of the surrounding materials. Recently we reported [1,2] a four-fold increase in the friction coefficient of La0.7Sr0.3MnO3 as it is heated through the metal-insulator transition (MIT) and a two-fold increase upon resistively switching a La0.55Ca0.45MnO3-film. Possible contributions from electrostatic forces and electronic and phononic dissipation were considered, with the conclusion that only dissipation via phononic channels were of the necessary order of magnitude.
To investigate the role of depleted surface layers and test the idea of phononic dissipation channels, temperature-dependent friction measurements near the MIT of a (La0.6Pr0.4 )0.67Ca0.33MnO3 film were performed. However, the friction shows no evidence of the MIT and instead decreases continuously with temperature in accordance with the well known thermal lubricity effect [3]. Measurements of the effect of applied voltage on adhesion and friction indicate an insulating surface layer on the metallic phase, which may obscure possible changes in the friction of the film at the phase transformation.
[1] H. Schmidt et al., arXiv:1611.02684; [2] H. Schmidt, Ph.D. thesis, University Göttingen, (2018); [3] Barel et al., Tribology Letters, 39(3), 311-319, (2010).