In situ tuning of magnetization via topotactic lithium insertion in ordered mesoporous lithium ferrite thin films. Issue 38 (8th August 2016)

• Record Type: Journal Article
• Authors: Reitz, Christian; Suchomski, Christian; Wang, Di; Hahn, Horst; Brezesinski, Torsten
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 38(2016)
• Page Start: 8889
• Page End: 8896
• Publication Date: 2016-08-08
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tc02731h
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Topotactic Li insertion into polymer-templated mesostructured α-LiFe5 O8 thin films allows for the intriguing possibility of tuning the magnetization at room temperature. Abstract : The synthesis and characterization of cubic mesostructured lithium ferrite (α-LiFe5 O8 ) with 20 nm diameter pores and nanocrystalline walls is reported. The material is prepared in the form of thin films by sol–gel dip-coating using a poly(isobutylene)- block -poly(ethylene oxide) amphiphilic diblock copolymer as the porogen. Electron microscopy, X-ray scattering and diffraction, time-of-flight secondary ion mass spectrometry, Raman and X-ray photoelectron spectroscopy all show that α-LiFe5 O8 can be templated to produce high-quality films that are chemically and phase-pure and thermally stable to over 600 °C. Magnetometry measurements indicate ferrimagnetic behavior below 300 K, with the coercivity exhibiting a T 1/2 dependence. This novel mesoporous spinel material – when used as an electrode in secondary battery cells – can reversibly store charge via topotactic Li insertion, which allows for the intriguing possibility of tuning the magnetization at room temperature in a facile and controlled manner. The general approach is simple and should be applicable to a variety of other magnetic materials that are capable of reacting electrochemically with Li to produce reduced phases.