TY - JOUR
T1 - Tropochemical Cell-Twinning in the New Quaternary Bismuth Selenides K xSn6-2xBi2+xSe9 and KSn 5Bi5Se13
AU - Mrotzek, Antje
AU - Kanatzidis, Mercouri G.
PY - 2003/11/3
Y1 - 2003/11/3
N2 - The quaternary KxSn6-2xBi2+xSe 9 were discovered from reactions involving K2Se, Bi 2Se3, Sn, and Se. The single crystal structures reveal that KxSn6-2xBi2+xSe9 is isostructural to the mineral heyrovskyite, Pb6Bi2S 9, crystallizing in the space group Cmcm with a = 4.2096(4) Å, b = 14.006(1) Å, and c = 32.451(3) Å while KSn5Bi 5Se13 adopts a novel monoclinic structure type (C2/m, a = 13.879(4) Å, b = 4.205(1) Å, c = 23.363(6) Å, β = 99.012(4)°). These compounds formally belong to the lillianite homologous series xPbS·Bi2S3, whose characteristic is derivation of the structure by tropochemical cell-twinning on the (311) plane of the NaCl-type lattice with a mirror as twin operation. The structures of KxSn6-2xBi2+xSe9 and KSn 5Bi5Se13 differ in the width of the NaCl-type slabs that form the three-dimensional arrangement. While cell-twinning of 7 octahedra wide slabs results in the heyrovskyite structure, 4 and 5 octahedra wide slabs alternate in the structure of KSn5Bi5Se 13. In both structures, the Bi and Sn atoms are extensively disordered over the metal sites. Some physicochemical properties of K xSn6-2xBi2+xSe9 and KSn 5Bi5Se13 are reported.
AB - The quaternary KxSn6-2xBi2+xSe 9 were discovered from reactions involving K2Se, Bi 2Se3, Sn, and Se. The single crystal structures reveal that KxSn6-2xBi2+xSe9 is isostructural to the mineral heyrovskyite, Pb6Bi2S 9, crystallizing in the space group Cmcm with a = 4.2096(4) Å, b = 14.006(1) Å, and c = 32.451(3) Å while KSn5Bi 5Se13 adopts a novel monoclinic structure type (C2/m, a = 13.879(4) Å, b = 4.205(1) Å, c = 23.363(6) Å, β = 99.012(4)°). These compounds formally belong to the lillianite homologous series xPbS·Bi2S3, whose characteristic is derivation of the structure by tropochemical cell-twinning on the (311) plane of the NaCl-type lattice with a mirror as twin operation. The structures of KxSn6-2xBi2+xSe9 and KSn 5Bi5Se13 differ in the width of the NaCl-type slabs that form the three-dimensional arrangement. While cell-twinning of 7 octahedra wide slabs results in the heyrovskyite structure, 4 and 5 octahedra wide slabs alternate in the structure of KSn5Bi5Se 13. In both structures, the Bi and Sn atoms are extensively disordered over the metal sites. Some physicochemical properties of K xSn6-2xBi2+xSe9 and KSn 5Bi5Se13 are reported.
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U2 - 10.1021/ic034252n
DO - 10.1021/ic034252n
M3 - Article
C2 - 14577789
AN - SCOPUS:0242290393
SN - 0020-1669
VL - 42
SP - 7200
EP - 7206
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 22
ER -