Magnetic transparent conducting oxide film and method of making
US6761985B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2001 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Oct 4, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12736
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Cobalt-nickel oxide films of nominal 100 nm thickness, and resistivity as low as 0.06 &OHgr;·cm have been deposited by spin-casting from both aqueous and organic precursor solutions followed by annealing at 450° C. in air. Films deposited on sapphire substrates exhibit a refractive index of about 1.7 and are relatively transparent in the wavelength region from 0.6 to 10.0 &mgr;m. They are also magnetic. The electrical and spectroscopic properties of the oxides have been studied as a function of x=Co/(Co+Ni) ratio. An increase in film resistivity was found upon substitution of other cations (e.g., Zn2+, Al3+) for Ni in the spinel structure. However, some improvement in the mechanical properties of the films resulted. On the other hand, addition of small amounts of Li decreased the resistivity. A combination of XRD, XPS, UV/Vis and Raman spectroscopy indicated that NiCo2O4 is the primary conducting component and that the conductivity reaches a maximum at this stoichiometry. When x<0.67, NiO forms leading to an increase in resistivity; when x>0.67, the oxide was all spinel but the increased Co content lowered the conductivity. The influence of cation charge state and site o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.