Effects of the antiferromagnetic anti-phase domain boundary on the magnetization processes in Ni2Mn(Ga0.5Al0.5) Heusler alloy

The effects of anti-phase domain (APD) boundaries on the magnetic properties of Ni2Mn(Ga0.5Al0.5) alloy were studied by magnetic measurements and transmission electron microscopic observations. The growth of APDs at 773 K followed the square root law for annealing time. While the saturation magnetization and the Curie temperature were hardly affected by the APD size, the magnetization curve in the specimen with smaller mean APD size became harder, caused by the pinning effect of the magnetic domain walls due to the APD boundaries.

► Size effects of anti-phase domain (APD) boundaries on the magnetic properties were examined.
► The growth of APDs at 773 K follows the square root law for annealing time.
► The saturation magnetization and the Curie temperature are hardly affected by the APD size.
► Magnetization process is affected by the antiferromagnetic APD boundaries.