CHANGE IN VOLUME ON ORDERING OF Fe-(50-80 at%)Pd SUPERLATTICE ALLOYS.

The lattice constants and thermal expansion have been measured. Volume of the 70 and 80 at%Pd alloys decreases at the order-disorder transition temperature on ordering, and expansivity decreases as the long-range order parameter increases. The volume decrease due to ferromagnetism occurs at the magnetic transition temperature in the ordered and disordered phases. Volume at room temperature is smaller in the ordered phase than in the disordered phase.