GeSb 4 Te 4 – a New 9 P ‐Type Phase in the System Ge/Sb/Te

9 P ‐GeSb 4 Te 4 is a new germanium antimony telluride that can be obtained from the elements as a homogeneous phase by quenching a stoichiometric melt and subsequently annealing the sample at 500 °C. The crystal structure consists of alternating antimony layers similar to those in elemental antimony and rocksalt‐type blocks similar to those in GeSb 2 Te 4 . Although not thermodynamically stable according to the phase diagram, GeSb 4 Te 4 is remarkably stable up to 540 °C, where it starts to melt incongruently according to DSC and DTA measurements. The crystal structure has been refined from single‐crystalX‐ray data [ P $\bar{3}$ m 1, a = 4.2466(2) Å, c = 17.483 Å, R 1 = 0.0355]. Its diffraction patterns are very similar to those of other 9 P ‐type tellurides like Ge 2 Sb 2 Te 5 and Sb 2 Te, which tend to occur as very pronounced false minima in structure refinements. The electrical conductivity is low (33 S · cm –1 ) but exhibits metallic temperature dependence.