Atomic ordering and magnetic properties in Ni2Mn(GaxAl1−x) Heusler alloys

✍ Scribed by H. Ishikawa; R.Y. Umetsu; K. Kobayashi; A. Fujita; R. Kainuma; K. Ishida

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 539 KB
• Volume: 56
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.05.034

✦ Synopsis

The phase stability and magnetic properties of Ni 2 Mn(Ga x Al 1Àx ) alloys were studied by differential scanning calorimetric and magnetometric measurements, and X-ray diffraction and transmission electronic microscopic observations. The order-disorder transition temperature from the B2 to the L2 1 phase, T B2=L2 1 t , linearly increases with increasing x and the magnetic properties depend on the annealing conditions. Especially in the Ni 2 Mn(Ga 0.5 Al 0.5 ) alloy, the condition of the atomic order can be varied from a B2 to an L2 1 structure by the annealing temperature. The magnetic property of the fully ordered L2 1 phase is ferromagnetic with a Curie temperature T C of about 380 K, while that in the B2 phase is antiferromagnetic with the Ne ´el temperature T N of about 300 K.