Entropic stabilization and retrograde solubility in Zn_4Sb_3
Zn_4Sb_3 is shown to be entropically stabilized versus decomposition to Zn and ZnSb through the effects of configurational disorder and phonon free energy. Single-phase stability is predicted for a range of compositions and temperatures. Retrograde solubility of Zn is predicted on the two-phase boundary region between Zn_4Sb_3 and Zn. The complex temperature-dependent solubility can be used to explain the variety of nanoparticle formation observed in the system: formation of ZnSb on the Sb-rich side, Zn on the far Zn-rich side, and nano-void formation due to Zn precipitates being reabsorbed at lower temperatures.
Additional Information© 2011 American Physical Society. Received 21 October 2010; revised 12 January 2011; published 4 March 2011. This work is supported by the US National Science Foundation via Grant No.DMR-0953378, through TeraGrid resources at NCSA and SDSC under Grant No. TG-DMR050013N, and the ARO-MURI Materials on the Brink and the DARPA Nano Materials Program.
Published - Pomrehn2011p13222Phys_Rev_B.pdf