RADIOACTIVE MICROSPHERE AND METHOD FOR PREPARATION THEREOF

摘要

A microsphere which is capable of irradiating radioactive rays in a human bo dy for a long period of time, is excellent in chemical durability, and has a diameter of 1 to 100 .mu.m, characterized in that it comprises 99 wt % or mo re of a crystal of an oxide which contains 47 wt % or more of radioactive yttrium, such as Y2O3 or YPO4, the balance being inevitable impurities.