Structure and physical properties of modified Ti2MnAl compound – Ti2Fe0.5Cr0.5Al and Ti2MnAl0.5In0.5 case

Ti2MnAl was believed to be Spin Gapless Semiconducting (SGS) material, but this state can be achieved only in an inverted variant of Heusler structure. This specific structure is not realized under normal conditions, however, earlier reports suggest that substituting Al by In or Sn should make it possible. This was the motivation for studying the structural and physical properties of Ti2MnAl0.5In0.5 alloy in this paper. We also studied isoelectronic Ti2Fe0.5Cr0.5Al material, as it is well known that properties of Heusler compounds strongly depend on the valence electron count. We report a combined experimental and theoretical study, where we synthesized substituted variants and measured their diffraction patterns. Additionally we performed ab initio calculations using several methods to study the stability of the resulting compounds. We also examined the impact of disorder within Coherent Potential Approximation. Experimental XPS (X-ray Photoemission Spectroscopy) spectra, magnetic susceptibility and electrical resistivity are also discussed. [Display omitted] •He successful synthesis of Ti2Fe0.5Cr0.5Al and Ti2MnAl0.5In0.5•DFT calculations for substituted structure variants using three methods.•Regular Heusler structure is preferred for substituted variants.•Impact of disorder on the preferred crystal structure.•Both materials are paramagnetic metals, as expected for regular structure.