The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 2011
Filed:
Dec. 20, 2006
Bing Han, Lansdale, PA (US);
Jonathan H. Tao, Oceanside, CA (US);
Madis Raukas, Charlestown, MA (US);
Keith A. Klinedinst, Hudson, MA (US);
Jan B. Talbot, San Diego, CA (US);
Kailash A. Mishra, North Chelmsford, MA (US);
Bing Han, Lansdale, PA (US);
Jonathan H. Tao, Oceanside, CA (US);
Madis Raukas, Charlestown, MA (US);
Keith A. Klinedinst, Hudson, MA (US);
Jan B. Talbot, San Diego, CA (US);
Kailash A. Mishra, North Chelmsford, MA (US);
OSRAM SYLVANIA Inc., Danvers, MA (US);
The Regents of the University of California, La Jolla, CA (US);
Abstract
Rare earth-activated aluminum nitride powders are made using a solution-based approach to form a mixed hydroxide of aluminum and a rare earth metal, the mixed hydroxide is then converted into an ammonium metal fluoride, preferably a rare earth-substituted ammonium aluminum hexafluoride ((NH)AlREF), and finally the rare earth-activated aluminum nitride is formed by ammonolysis of the ammonium metal fluoride at a high temperature. The use of a fluoride precursor in this process avoids sources of oxygen during the final ammonolysis step which is a major source of defects in the powder synthesis of nitrides. Also, because the aluminum nitride is formed from a mixed hydroxide co-precipitate, the distribution of the dopants in the powder is substantially homogeneous in each particle.