The Structural, Electronic, Magnetic, Thermodynamic, and Mechanical Properties of Quaternary Heusler Alloys TiHfIrZ (Z = Al, Ga, In)

The structural, electronic, magnetic, thermodynamic, and mechanical properties of the hypothetical quaternary Heusler alloys (QHAs) TiHfIrZ (Z = Al, Ga, In) have been investigated by first-principles calculations within generalized gradient approximation (GGA) method. Since the QHAs TiHfIrZ (Z = Al, Ga, In) are not studied experimentally and theoretically so far, we first research that the most stable configurations of the QHAs TiHfIrZ (Z = Al, Ga, In) are all Y-type (I) in ferromagnetic (FM) phase. The large absolute values of both negative formation energy and positive cohesion energy verify the thermodynamic stabilities of the QHAs TiHfIrZ (Z = Al, Ga, In). The higher than the room-temperature Curie temperatures TC, as large as 2 μB/f.u total magnetic moments per formula unit and the half-metallic (HM) characters, indicate the QHAs TiHfIrZ (Z = Al, Ga, In) can be used in the magnetoelectronics and spintronics fields. The QHAs TiHfIrZ (Z = Al, Ga, In) have mechanical stabilities, ductility, and high hardness. The lattice constant regions of maintaining the HM characters are 5.722–6.405 Å, 5.786–6.402 Å, and 5.839–6.589 Å for QHAs TiHfIrZ (Z = Al, Ga, In), respectively.