Magnetic structural transformation induced by magentic field and temperature in Gd_5Ge_4

Recent research have shown that the first order magnetic structural transition in Gd5Ge4 can be arrested at low temperatures and low magnetic fields.This effect gives rise to a low temperature magnetic glass state with ferromagnetic clusters embedded in antiferromagnetic matrix.Based on this new result,we have found that Gd5Ge4 undergoes reversible and irreversible magnetic structural phase transformations in different measuring conditions.It is shown that the magnetic behaviors are related to the structure transition.The first order magnetic structural phase transition plays an important role to the giant magnetocaloric effect.