Magnetostructural transformation and magnetocaloric effect in melt-spun and annealed Mn1−xCuxCoGe ribbons

The melt-spun and annealed Mn1−xCuxCoGe ribbons are prepared. The magnetic and magnetocaloric properties of these ribbons was investigated by magnetic, calorimetric and structural measurements. In contrast with the melt-spun ribbons, a coupled magnetostructural transformation between the ferromagnetic TiNiSi-type and paramagnetic Ni2In-type state is achieved in the annealed Mn1−xCuxCoGe (x = 0.02, 0.04) ribbons. Accordingly, the large enhancement of magnetic entropy change peak values from the melt-spun to annealed ribbons is observed. The origins of the first-order magnetostructural transformation in annealed ribbons are discussed.