摘要 |
A controlled release glass is based on phosphorus pentoxide as the glass forming oxide and an alkali metal oxide as the principal glass modifier. The glass contains a modifying oxide of a material to be released slowly, e.g. one of the oxides of the alkali metal, or an oxide of an alkaline earth metal, an oxide of a metal of Group IIIA of the Periodic Table or a transition metal oxide, depending on the deficiency to be cured. |