CHEMICAL-ANALYSIS OF RARE-EARTH-IRON MAGNETOSTRICTION ALLOYS BY ICP-AES USING AN INTERNAL STANDARD

Rare earth-iron magnetostriction alloy (0.1 g) was decomposed with hydrochloric acid and hydrogen peroxide within a few minutes. The solution obtained was diluted to 100 ml with water. To 10 ml of this diluted solution, an internal standard solution and hydrochloric acid were added and then diluted to 100 ml again with water. The amounts of Mn, Fe, Tb and Dy were measured by ICP-AES without any concomitant effect. Among the internal standard elements investigated (Sc, Y and La), La was most suitable. Recoveries of each element measured with a synthetic sample solution were over 99.7%. The relative standard deviations (n=5) were 0.04% approximately 0.35%.