Plasma-Assisted Chemical Vapor Deposition of F-Doped MnO2 Nanostructures on Single Crystal Substrates

Abstract

<jats:p>MnO2 nanostructures were fabricated by plasma assisted-chemical vapor deposition (PA-CVD) using a fluorinated diketonate diamine manganese complex, acting as single-source precursor for both Mn and F. The syntheses were performed from Ar/O2 plasmas on MgAl2O4(100), YAlO3(010), and Y3Al5O12(100) single crystals at a growth temperature of 300 °C, in order to investigate the substrate influence on material chemico-physical properties. A detailed characterization through complementary analytical techniques highlighted the formation of highly pure and oriented F-doped systems, comprising the sole β-MnO2 polymorph and exhibiting an inherent oxygen deficiency. Optical absorption spectroscopy revealed the presence of an appreciable Vis-light harvesting, of interest in view of possible photocatalytic applications in pollutant degradation and hydrogen production. The used substrates directly affected the system structural features, as well as the resulting magnetic characteristics. In particular, magnetic force microscopy (MFM) measurements, sensitive to the out-of-plane magnetization component, highlighted the formation of spin domains and long-range magnetic ordering in the developed materials, with features dependent on the system morphology. These results open the door to future engineering of the present nanostructures as possible magnetic media for integration in data storage devices.</jats:p>

A chemist's guide to photoelectrode development for water splitting – the importance of molecular precursor design

“…[207][208][209][210] Fluoroalkoxides are also hydrophobic, providing additional stability against hydrolysis from atmospheric moisture. 207 While fluorinated ligands are sometimes reported in SSPs for fluorine-doped materials, 211 most commonly fluorinedoped tin oxide (FTO), 212,213 it is feasible to fabricate thin films without fluorine incorporation despite using fluorinated precursors. The strong C-F bond means complexes will thermally decompose into more stable fluorine-containing fragments, removing the fluorine atoms as process-inert by-products and preventing incorporation into the film.…”