Phase Studies in the Binary System MgO–Ta ₂ O ₅

Abstract

The objective of this investigation was to determine subsolidus phase relations in the system MgO–Ta 2 O 5 and to obtain accurate crystallographic data on the compounds formed. MgO and Ta 2 O 5 formed three compounds: Mg 4 Ta 2 O 9 , Mg 3 Ta 2 O 8 , and MgTa 2 O 6 . Mg 4 Ta 2 O 9 and MgTa 2 O 6 appeared to be stable up to their melting points, whereas Mg 3 Ta 2 O 8 was stable only between 1475° and about 1675°C. X‐ray diffraction and density data are presented for the three compounds.