Dynamics of AC susceptibility and coercivity behavior in nanocrystalline TbAl1.5Fe0.5 alloys

► Bulk and nanocrystalline TbAl1.5Fe0.5 alloys. ► Enhancement of the magnetic properties when Fe substitutes Al in bulk TbAl2, with a glassy behavior below 54 K. ► AC susceptibility of nanocrystalline TbAl1.5Fe0.5 alloys shows atypical frequency-dependent contributions. ► The nanoparticles show a single domain behavior. ► An interplay of magnetocrystalline anisotropy and exchange interactions with size and disorder effects is suggested.