Erscheint 4 Ausgaben pro Jahr
ISSN Druckformat: 1093-3611
ISSN Online: 1940-4360
Indexed in
Plasma sprayed ceramics for low macroscopic field emitters
ABSTRAKT
Plasma sprayed coatings have been investigated as field emission cathodes. The tested materials were Al2O3+13%TiO2, Al2O3+40%TiO2, TiO2. Some of these coatings were laser engraved. The samples used were initially prepared for purposes other than field emission and their components and structures were not optimised for electron emission. The emission properties were evaluated from current-voltage characteristics taken in a diode configuration in a vacuum chamber under a pressure of 1×10−6 Pa. Preliminary results indicate that some layers are good field emitters (threshold field 1×10−7 V/m for Al2O3+13%TiO2). The emission stability was generally good and the emission curves were similar on repetition. No significant hysteresis in I-V plots for "up-and-down" measurements was noticed. A model of possible mechanism of low microscopic field emission is presented and microstructural investigations using techniques of XRD, Raman spectroscopy and SEM techniques of plasma sprayed and laser engraved layers enabled understanding of increase of field enhancement factor.
-
Znamirowski Z., Ladaczek M., Lighting segment with field electron titania cathode made using suspension plasma spraying, Surface and Coatings Technology, 202, 18, 2008. Crossref