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Phosphor Preparation Process

IP.com Disclosure Number: IPCOM000096132D
Original Publication Date: 1963-Jan-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Vogl, MJ: AUTHOR

Abstract

This method provides firing schedules for selected phosphors to broaden their spectrum of activation. A critical firing temperature range exists for such phosphors as yttrium tungstates and lanthanum tungstates. Their activation spectrum is broadened when they are fired preferentially at from 1000 degrees to 1050 degrees C for 10 to 30 minutes in the process of reducing them to powder form. Firing schedules above or below this median range detract from the width of the exciting UV spectrum.

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Phosphor Preparation Process

This method provides firing schedules for selected phosphors to broaden their spectrum of activation. A critical firing temperature range exists for such phosphors as yttrium tungstates and lanthanum tungstates. Their activation spectrum is broadened when they are fired preferentially at from 1000 degrees to 1050 degrees C for 10 to 30 minutes in the process of reducing them to powder form. Firing schedules above or below this median range detract from the width of the exciting UV spectrum.

For instance, a broad-band phosphor call be prepared by adding one mole of Y(2)O(3) to one mole of H(2)WO(4) and firing this for 10 to 30 minutes at a temperature within the 1000 degrees -1050 degrees C range. This phosphor exhibits good fluorescent response at both short and long wave length UV. Firing at over about 100 degrees less than this temperature preferentially reduce s the long wave length UV response. At over about 100 degrees higher than this range, it reduces the short wave length UV response. Adding a a 10% by weight amount of lithium bromide to the preparation does not effect this firing schedule response.

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