Low temperature preparation of orthoferrite thin-films by an inorganic sol-gel process

Aqueous precursor sets of orthoferrites were prepared by room temperature p rocessing of inexpensive commercially available metal salts. Crystalline th in-films of orthoferrites of general formula, LnFeO(3)(Ln = La, Nd, Sm, Gd, Dy, Er, Yb and Y) were prepared by dip-coating with the precursor sol and heating at 650 degreesC. All the films showed >80% transmittance independen t of the rare earth ion. The optical band-gap was 3.1 eV and the refractive index was 1.61 +/- 0.02 independent of the rare earth ion. The films exhib ited uniformity in thickness. mechanical and thermal integrity upon heating . (C) 2001 Elsevier Science B.V. All rights reserved.