文件类型:PDF文档
文件大小:388K
FIELD : medicine; chemistry.
SUBSTANCE : inventions relate to inorganic chemistry and medicine and can be used during the manufacturing of scintillators. First, the powder of general formula is obtained M1aM2bM3cM4dO12 (1), where O is oxygen; M1, M2, M3 and M4 – metals, which are different from each other; the sum of a+b+c+d is about 8; "a" is from 2 to 3.5; "b" is from 0 to 5; "c" is from 0 to 5; "d" is from 0 to 1; while "b" and "c", "b" and "d" or "c" and "d" can not be simultaneously equal to zero; M1 is a rare earth element, including gadolinium, yttrium, lutetium, scandium or a combination thereof; M2is aluminum or boron; M3 is gallium; M4 is a coactivator, which is selected from thallium, copper, silver, lead, bismuth, indium, tin, antimony, tantalum, tungsten, strontium, barium, boron, magnesium, calcium, cerium, yttrium, scandium, lanthanum, lutetium, praseodymium, terbium, ytterbium, samarium, europium, holmium, dysprosium, erbium, thulium or neodymium. Average particle size of the powder is from 5 nm to 500 mcm. Resulting powder is heated to 500–2, 000 °C for its melting, and the resulting melt – up to 800–1, 700 °C in the oxygen-containing atmosphere. During the subsequent stage, polycrystals or single crystals of garnets are obtained. For example, the garnets can have the following compositions : Gd3Al2Ga3O12, Gd3Ga2, 5Al2, 5O12, Gd1, 5Y1, 5Ga2, 5Al2, 5O12 or Gd1, 5Lu1, 5Al1, 5Ga1, 5O12 and are used in the products such as the imaging device or the tomography device.
EFFECT : loss of gallium decreases when the crystals are obtained.
19 cl