Magnetic and transport properties of inverse Heusler compound Cr2CoAl

Abstract

We report magnetic and electrical transport properties of polycrystalline as-cast compound Cr2CoAl having inverse Heusler like XA structure with B2 disorder. Temperature-dependent magnetization (M-T) under zero-field cooled (ZFC) and field cooled (FC) condition and field-dependent magnetization (M-H) studies suggest that this compound is a soft magnetic material below Tc ~ 20.5 K having a very low magnetic moment as it is found that magnetization at 5 K under 50 kOe applied magnetic field is ~0.11μB/f.u. Also, M-T data taken ZFC-FC condition under different applied magnetic fields and M-H data taken at 100 K and 300 K indicate that this compound may have magnetic clusters in paramagnetic matrix. Further analysis and temperature-dependent heat capacity measurement reveal paramagnetic to a short-range ordered ferromagnetic transition near Tc ≈ 20.5 K and also reveal the presence of magnetic clusters within the compound. These magnetic clusters may arise because of B2 disorder in the compound. Temperature-dependent resistivity measurement confirms that the compound Cr2CoAl is metallic as it is found increasing with temperature. Nonlinearity in temperature dependency resistivity data, observed in low- temperature region, follows T2 dependency that generally comes because of electron–electron scattering. Magneto-resistance (MR) is also found to be positive throughout the temperature region from 8 K to 390 K.