Investigation of ZrFe2 and ZrCo2 under very high pressure of gaseous hydrogen and deuterium

New hydrides and deuterides of Laves cubic phases ZrFe2 and ZrCo2 were synt hesized by high hydrogen (deuterium) pressure technique. For both Laves pha ses the symmetry of lattice does not change but a large expansion of lattic e parameter (by 8% for ZrFe2 and by 4.5% for ZrCo2) occurs during hydrides (deuterides) formation. In contrast to the relatively stable hydride (if st ored in an inert atmosphere) formed in ZrFe2, the ZrCo2H2 decomposes easily at 25 degreesC. Large lattice expansion of ZrFe2 during the deuteride form ation changes only slightly its magnetic properties.