Mg vacancy and dislocation strains as strong phonon scatterers in Mg2Si1−xSbx thermoelectric materials

The high contents of aliovalent Sb alloying in Mg2Si not only result in Mg vacancy, but also induce dense dislocations with intensive strain accumulation, which act as extra phonon scatterers and contribute to the significantly reduced lattice thermal conductivity in the Sb alloyed Mg2Si, compared to the Sn alloyed Mg2Si with the same amount of Si sites substituted.175