Improvements in or relating to Luminescent Compositions of Matter

摘要

1,175,573. Luminescent materials. WESTERN ELECTRIC CO. Inc. 21 March, 1967 [1 April, 1966], No. 13093/67. Heading C4S. [Also in Division H1] Aluminescent composition includes trivalent Yb and trivalent Tm in an amount, of the cations present, of at least 0.6% Yb ions and at least 0À01% of Tm. Cr may be present in amount 0.1 to 1.0% of the cations present. A preferred composition is (M a Yb b Tm c )-Me 5 O 12 , where M may be Y, Gd, Lu or mixtures thereof, Me may be trivalent Ga and/or Al alone or in combination with Cr in an amount 0.16 to 1À6 atom per cent of the Ga and/or A1 and a+b+c= 3, a is 0 to 2.949, preferably 1.3 to 2.87, b is 0.05 to 2.999, preferably 0.1 to 1.5 and c is 0À0008 to 1.0, preferably 0À01 to 0.6. The composition may be used in a laser and a tungsten lamp operating at 3000‹ K is a preferred pump source. Exemplary environments include ABO 4 , where A is Ca, Sr, Ba or Pb; B is Mo or W; MC 2 O 6 where M is Y, Gd, La or mixtures thereof and C may be Ti, Sn, Si, Ge, or Zr; MDO 3 , where M is as above and D is Al, Ga, Sc, Lu, La, Y, Bo, Gd; and a garnet system such as YAG. In an embodiment, starting materials are heated to 1300‹ C. and cooled at ¢‹/hour to 950‹ C., the flux drained and crystals cooled to yield Y 2À47 Yb 0À5 Tm 0À03 Al 5 O 12 emitting at 1.88 and 2.01 microns at liquid nitrogen temperature and 2.01 microns at room temperature.