Detailed magnetic measurements on intermetallic ${\text{Fe}}_2\text{VAl}$ Heusler type alloys are presented. Annealed ${\text{Fe}}_2\text{VAl}$ sample is structurally better ordered and exhibits higher magnetization, resistivity and magnetoresistance values compared to as cast samples. From the systematic analysis of magnetization and electrical transport data it has been established that the ${\text{Fe}}_2\text{VAl}$ behaves more like a cluster glass. Magnetization as a function of magnetic field at various temperatures suggests the presence of superparamagnetic clusters along with paramagnetic background. Arrot plots confirm the absence of spontaneous magnetic moment and hence long-range ferromagnetic order down to 5 K. The field cooled and zero-field-cooled magnetization curves suggest the superparamagnetic entities freeze below 10 K. Our magnetoresistance data corroborate the magnetization results and confirm the presence of magnetic clusters.

• Received 26 December 2007

DOI:https://doi.org/10.1103/PhysRevB.78.064401