Magnetocaloric effect in amorphous-crystalline microcircuits PrDyFeCoB

In amorphous-crystalline PrDyFeCoB microconductors obtained by ultrafast melt cooling, a negative magnetocaloric effect was detected at 200–250 K (with heat release when the magnetic field is turned on), as well as a positive magnetocaloric effect in the temperature range of 300–340 K (with heat absorption when the magnetic field is turned on). It is established that there are no phase transitions of the first kind in the studied temperature range, which indicates that both of the detected effects are associated with a change in the magnetic part of the entropy. The transition at 200–250 K is due to the presence of metamagnetic states induced by a magnetic field in the spin-glass state of the amorphous part of the PrDyFeCoB alloy, and with their transition to the ferrimagnetic state. The transition at 300–340 K is spin-reorientation, and it occurs in crystalline inclusions identified in the amorphous matrix.