Patent ID: 7399428

Claim:
A liquid flux method for producing powder materials selected from the group consisting of (Gd 1-x Bi x )V 1-y N y O 4 where 0.001<x<0.1 and 0.001<y<0.2; (Gd 1-x Bi x )V(O 4-z F z ) where 0.001<x<0.1, 0.001<z<0.2; and (Gd 1-x Bi x )V 1-y N y O 4-z F z where 0.001<x<0.1, 0.001<y<0.1, 0.001<z<0.1; wherein the method comprises the steps of: a) mixing Gd 2 O 3 , V 2 O 5 , VF 3 , VOF 3 , VN, and Bi 2 O 3 in desired weight ratios; b) blending a flux of LiCl and KCl in a 1:1 molar ratio with the mixture from step a); c) calcining and melting the mixed powders from step b) at about 400 to 700° C. for about 10 hours; d) washing the calcined material from step c) with deionized water to remove the flux; e) washing the resulting mixture from step d) in nitric acid, and then ammonia, to remove impurities; f) drying and grinding the material from step e); and g) calcining the material from step f) at about 800 to 1500° C. for about 5 to 10 hours.