| 摘要 |
<p>Luminescent materials, particularly suitable for emitting red light, consist of (a) the mixed rare earth oxides (RE1- xEux)2O3 where 25-100% of RE consists of one or more of the elements Sc, Y, La, Gd, Tb or Lu and the rest, if any, is Sm and/or Dy, and x is 0.03-0.8; or (b) oxysalts of these (RE1- xEux)2O3.A, where A is an oxyanion. The general method of preparation is the heating together in air of the separate oxides (usually in stoichiometric amounts, but slight departures are tolerated) or readily-decomposable compounds such as hydroxides, oxalates, carbonates, citrates, acetates or tartrates, the oxyanion where present being introduced either as oxides, such as oxides of tungsten, molybdenum, silicon, aluminium, boron, phosphorus, gallium or germanium or as acids or ammonium salts; alternatively preformed oxysalts can be heated together. Details of over 40 materials, and of their preparation, are given; the firing temperature ranges from 700-1500 DEG C., usually 1000 DEG C., and a second firing may be necessary. The resulting product is usually a single phase, but more than one phase may be present. The materials may be mixed with other luminescent materials such as calcium tungstate, barium-lead sulphate, antimony-and manganese-activated calcium halophosphates, selenium activated zinc sulphide or manganese-activated zinc-orthosilicate. They can then be dispersed in an organic or inorganic binder and coated on a substrate, or incorporated in a polymer (many examples of which are given), or between layers of a polymer, or in glasses or crystalline materials such as lithium fluoride or sodium chloride. The materials may be used in fluorescent discharge lamps, cathode-ray tubes, signs or luminescent articles. Titanium-activated alkaline earth selenides are referred to.ALSO:Luminescent materials, particularly suitable for emitting red light, consist of (a) the mixed rare earth oxides (RE1- xEux)2O3 where 25-100% of RE consists of one or more of the elements Sc, Y, La, Gd, Tb or Lu and the rest if any is Sm and/or Dy, and x is 0.03-0.8; or (b) oxysalts of these, (RE1- xEux)2O3 . A, where A is an oxyanion. The general method of preparation is the heating together in air of the separate oxides (usually in stoichiometric amounts, but slight departures are tolerated) or readily-decomposible compounds such as hydroxides, oxalates, carbonates, citrates, acetates or tartrates, the oxyanion where present being introduced either as oxides, such as oxides of tungsten, molybdenum, silicon, aluminium, boron, phosphorus, gallium or germanium or as acids or ammonium salts; alternatively preformed oxysalts can be heated together. Details of over 40 materials, and of their preparation, are given; the firing temperature ranges from 700 DEG -1500 DEG C., usually 1000 DEG C., and a second firing may be necessary. The resulting product is usually a single phase, but more than one phase may be present. The materials may be dispersed in glasses or crystalline materials such as lithium fluoride or sodium chloride.</p> |
