| 摘要 |
<p>High-luminescence phosphors comprise terbium and/or cerium activated ternary lutetium-gadolinium-yttrium silicates. Pref. the ternary silicates have an orthosilicatic structure and the phosphors are represented by (LuxGdyYz)2SiO5:aTb, bCe where x+y+z = 1, x = 0-1, y = 0-1, z = 0-1, a = 0.3, b = 0-0.01 and a+b does not equal 0. Pref. x = 0.15-0.45, y = 0.15-0.45, z = 0.15-0.45, a = 0.01-0.2 and b = 0.0008-0.0012. A gel process (claimed) for producing the phosphors has the steps of:- (a) dissolving lutetium, gadolinium and yttrium oxides and terbium and/or cerium oxides in dild. nitric acid; (b) adding tetraethylorthosilicate and alcohol; (c) adding excess ammonia to form a gel; (d) drying the gel at 70 deg.C for 3-4 days; (e) firing the dried gel for several periods at gradually increasing temps. up to 1400-1600 deg.C, either in air or in argon, nitrogen, nitrogen-hydrogen, or nitrogen-carbon oxides atmos. The gel process ensures that the silicates have predominantly the desired orthosilicatic structure rather than the apathetic structure.</p> |
