Abstract
The structural, electronic, magnetic, optical, and thermoelectric properties of EuGa2X2 (X P, As, and Sb) are investigated using first principles calculations (taking into account the onsite Coulomb interaction) and the semi-classical Boltzmann theory. The divalent nature of Eu fulfils the Zintl principle as is confirmed by the calculated total magnetic moments of similar to 7 mu(B). A metallic behavior is obtained for all compounds. The optical spectra originate mainly from the transitions between occupied Eu 4f states and unoccupied Eu 5d states. It is demonstrated that the two-dimensional [Ga(P/As)](2) network in EuGa2P2 and EuGa2As2 is favorable for thermoelectric applications as compared to the three-dimensional [GaSb](2) network in EuGa2Sb2. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767363]