Site preference, thermodynamic, and magnetic properties of the ternary Laves phase Ti(Fe1 – x Al x )2 with the crystal structure of the MgZn2-type

Abstract

Abstract Site preference and thermodynamic properties of the ternary Laves phase Ti(Fe1 –x Al x )2 with MgZn2-type have been studied employing Rietveld refinement of X-ray and neutron powder diffraction data, X-ray single crystal data, and isoperibolic drop calorimetry techniques. A detailed relation between lattice parameters of Ti(Fe1– x Al x )2 and the Al content in the Laves phase has been presented. The Rietvelt refinement revealed that Ti atoms occupy the 4f site in the MgZn2-type, whilst Fe and Al atoms randomly share the 2a and 6 θ site. Heat of formation has been measured for Ti(Fe0.5Al0.5)2. For the ab initio density functional theory applications, a large number of structural models were investigated to calculate the concentration dependent (Al) heats of formation, magnetic structural stabilities, lattice parameters, and site occupancies, which are in good agreement with experiment.