• Valeanu, Mihaela
• Tolea, Felicia
• Sofronie, Mihaela
• Kuncser, Victor

Abstract

<jats:p>Two series of cobalt substituted Ni–Fe–Ga ferromagnetic shape memory alloys with lower gallium content (&amp;lt;27 at. %) were studied by differential scanning calorimetry, x-ray diffraction, and thermomagnetic measurements. Co substitution for Fe or Ni promotes an increase in the Curie temperatures and a variation in the martensitic transformation (MT) temperatures, in accord with the alloy valence electron concentration change. For alloys with MTs below room temperature, a field dependent thermomagnetic hysteresis was evidenced and discussed in connection with the effect of cobalt substitution, on the magnetic hardness of the martensite phase. A direct interpretation of the evolution of the thermomagnetic hysteresis versus the applied field was provided.</jats:p>

Topics

• phase
• x-ray diffraction
• hardness
• differential scanning calorimetry
• cobalt
• Gallium
• Curie temperature