First-Principles Study on PdMnSn and PtMnSn Compounds in C1_b Structure

The phase stability, the electronic, mechanic and lattice dynamical properties of C1_b-type PdMnSn and PtMnSn compounds were investigated using first principles density functional calculations within the generalized gradient approximation. The computed lattice constants of PdMnSn and PtMnSn compounds were in line with the experimental and theoretical data in the published literature. The elastic constants in the C1_b structure for PdMnSn and PtMnSn compounds were carried out using the energy-strain method. The computed values of three independent elastic constants, both compounds are mechanically stable in the C1-type crystal structure and met the stability criteria. The electronic structure, total and partial density values of states, and total magnetic moment of these compounds were calculated and the evaluations were carried out by comparing with the existing results. Dynamic properties of PdMnSn and PtMnSn compounds were obtained using the density functional perturbation theory. Both of the compounds were dynamically stable due to the absence of the imaginary phonon frequencies. In addition, it was found that the compounds had a rapid rise in specific heat capacities from 0 to 300 K.