Proton presence and motion in rhenium-oxide films and their application to liquid-crystalline cells

M. Castriota, E. Cazzanelli, G. Das, R. Kalendarev, A. Kuzmin, S. Marino, G. Mariotto, J. Purans, N. Scaramuzza

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Disordered solid phases, containing appreciable amounts of hydrogen ions, are grown at the surface of rhenium oxide crystals, because of the high reactivity of this compound with ambient moisture. To investigate such phenomena, a comparative study is performed on ground powder and thermally evaporated or sputtered films using x-ray diffraction and micro-Raman spectroscopy. Two types of solid phases were found in the films: HxReO3 distorted perovskite structures, based on corner-sharing ReO6 octahedra as in the bulk crystals, and ordered HReO4 crystalline structures, based on tetrahedral perrhenate ions. The complex impedance measurements on ReO3 films support the hypothesis of mobile hydrogen ions in such defective films. Moreover, this relevant protonic conductivity allows the application of these films as active layers inserted into asymmetric nematic liquid-crystalline cells to rectify the electro-optical response of such devices, with performances quite similar to previously studied oxides such as WO3.

Original languageBritish English
Pages (from-to)1-15
Number of pages15
JournalMolecular Crystals and Liquid Crystals
Volume474
Issue number1
DOIs
StatePublished - Jan 2007

Fingerprint

Dive into the research topics of 'Proton presence and motion in rhenium-oxide films and their application to liquid-crystalline cells'. Together they form a unique fingerprint.

Cite this