Magnetic, thermodynamic, and electrical transport properties of AlFe₂B₂ based intermetallic compounds

Transition metal borides attracted considerable attention to the scientific community due to its potential applications, including a permanent magnet and cooling devices. AlFe₂B₂ is one such material that was initially reported by Jeitschko et al. (Acta Crystallogr., Sect. B: Struct. Sci, 25 (1969) 163). Recently, a large magnetocaloric effect near room temperature (Tan et al. JACS 135 (2013) 9553) was reported for the material. The crystal structure of AlFe₂B₂ based compounds adopts orthorhombic (space group Cmmm) with alternating Al monolayers and Fe₂B₂ slabs along the long b axis. Here we present the detailed study of the effect of substitution Fe by other 3d elements and B by p-block elements on magnetic, specific heat, and electrical transport properties of AlFe₂B₂ compound. We observed anomalous electrical transport behavior above and below the ferromagnetic to paramagnetic phase transition and transition temperature can be controlled by substitution.