M$ouml$ssbauer measurement of Curie temperatures and X-ray measurement of lattice parameters of some iron-palladium-hydrogen alloys

X-ray measurements on iron-palladium-hydrogen alloys containing up to 12·3 at.% Fe have enabled a phase diagram for these alloys to be constructed. The boundary between the α (low hydrogen content) and β (high hydrogen content) phases disappears for iron contents over 11·5 at.%. Mössbauer experiments confirm the existence of two phases up to this composition. Curie temperatures for the α-and β-phase hydrides and for hydrogen-free alloys have been measured by the Mössbauer technique and are compared with results obtained by other methods. Curie point measurements from Mössbauer spectra on equilibrium β-phase Fe-Pd-H show a change from a long- to short-range magnetic-ordering mechanism in the region 4 to 6 at.% Fe as the iron content is increased.