English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The crystal structure of Pb$_{10}$(PO$_4$)$_6$O, the proposed matrix for thepotential room-temperature superconductor LK-99, Pb$_{10-x}$Cu$_x$(PO$_4$)$_6$O($x = 0.9-1.0$), has been reinvestigated by single-crystal X-ray diffractionusing crystals prepared by Merker and Wondratschek (Z. Anorg. Allg. Chem. 1960,306, 25-29). The crystal structure is trigonal, P-3, a = 9.8109(6), c =14.8403(12) A, V = 1237.06(15) A3, R1 = 0.0413 using 3456 unique observedreflections. The crystal structure of Pb$_{10}$(PO$_4$)$_6$O is asuperstructure with regard to the standard P63/m apatite structure type. Thedoubling of the c parameter is induced by the ordering of additional O atomswithin the structure channels running parallel to the c axis and centered at(00z). The O atoms form short bonds to the Pb1 atoms, resulting in splittingthe Pb1 site into two, Pb1A and Pb1B. The structural distortions are furthertransmitted to the Pb phosphate framework formed by four Pb2 sites and PO$_4$groups. The structure data previously reported by Krivovichev and Burns (Z.Kristallogr. 2003, 218, 357-365) may either correspond to thePb$_{10}$(PO$_4$)$_6$O$_x$(OH)$_{2-x}$ ($x = 0.4$) member of thePb$_{10}$(PO$_4$)$_6$O-Pb$_{10}$(PO$_4$)$_6$(OH)$_2$ solid solution series, orto the high-temperature polymorph of Pb$_{10}$(PO$_4$)$_6$O (with the phasewith doubled c parameter being the low-temperature polymorph).

The crystal structure of Pb$_{10}$(PO$_4$)$_6$O revisited: the evidence of superstructure