1218
(Invited) Applying Energy Storage to Tune the Magnetism of Large-Pore Ordered Mesoporous Metal Oxide Thin Films

Tuesday, 30 May 2017: 15:10
Churchill C2 (Hilton New Orleans Riverside)
T. Brezesinski (Karlsruhe Institute of Technology, INT)
Polymer-templated mesostructured non-silicate oxide thin films have received much attention in the past on account of their potential for future device applications. However, despite the overall progress made in the synthesis of such materials, “complex” metal oxides are more often than not ill-defined from a structural point of view. The primary reasons are the lack of control over the hydrolysis and condensation reactions of the inorganic precursors used, and the fact that the crystallization of the nanoscale walls is difficult to control. In this talk I will describe the evaporation-induced self-assembly synthesis of cubic mesoporous La1–xCaxMnO3 (LCMO), La1–ySryMnO3 (LSMO) and LiFe5O8 (LFO) thin films using a polyisobutylene-block-poly(ethylene oxide) diblock copolymer as the structure-directing agent. Electron microscopy, GISAXS, XRD, XPS, RBS and SQUID magnetometry all show that these materials are of high quality and thermally stable to over 600 °C. More importantly, they can store charge by topotactic lithium insertion reaction (LFO) and via double-layer capacitance (LCMO/LSMO), which allows for the intriguing possibility of reversibly tuning the magnetization [1, 2]. Collectively, I will show that both approaches provide a method to exert fine control over magnetism in situ, and further might help to better understand (Faradaic) surface charge storage processes.

[1] C. Reitz, P. M. Leufke, R. Schneider, H. Hahn, T. Brezesinski, Chem. Mater. 26 (2014) 5745.

[2] C. Reitz, C. Suchomski, D. Wang, H. Hahn, T. Brezesinski, J. Mater. Chem. C 4 (2016) 8889.