Pages: 26 Published: Jan 1963
A large amount of research and development has been applied in the field of high-purity metals and compounds that has resulted in marked increases both in the purity of almost all materials and in the uses for them. The most noteworthy examples are perhaps those for materials termed semiconductors where a purity as great as nine-nines (99.9999999) has been claimed; thus the total impurity content claimed is one part in a billion (1 ppb). The need for analysis of high-purity materials has led to new or improved methods and techniques in extending the sensitivity for determining various constituents by chemical, spectrochemical, activation, solids mass spectrometric and resistivity methods. In all of these it often is necessary to use high-purity materials to prepare synthetic standards in the absence of analyzed samples. High purity in this report refers to a claimed purity of 99.9 per cent or greater. The results of the present survey, shown in Table 84, include 86 elements and compounds and over 1000 entries. The data have been assembled in tabular form beginning with actinium and continuing in alphabetical order through zirconium. Under each element, the metal is listed first, followed by the compounds, salts, or solutions, which are also alphabetized. Compounds are listed under the element of particular interest; for example, ammonium molybdate is listed under molybdenum, and potassium perrhenate under rhenium. Entries for a particular metal or compound are arranged in the order of decreasing purity as given by the supplier. Although some suppliers list several grades that could be listed for a particular material, in general, only the highest purity item has been included. When a supplier did not provide purity values, but listed materials as “spec pure”, ultra high purity, super purity, and other; these have been included on the judgment of the authors, but the purity was at least 99.9 per cent. Such entries generally have not been listed first nor last in order of purity, but have been interdispursed in a manner to suggest consideration of inquiry to the source for additional information that may be available.
Paper ID: STP48667S