DOE OSTI2020
BiPbSr2YCu2O8 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of two BiPbSr2YCu2O8 sheets oriented in the (0, 1, 0) direction. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.53–2.97 Å. In the second Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.56–2.97 Å. Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.30–2.58 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form corner-sharing CuO5 square pyramids. There are four shorter (1.92 Å) and one longer (2.49 Å) Cu–O bond lengths. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form corner-sharing CuO5 square pyramids. There are four shorter (1.95 Å) and one longer (2.31 Å) Cu–O bond lengths. Pb2+ is bonded in a 5-coordinate geometry to three O2- atoms. There are a spread of Pb–O bond distances ranging from 2.22–2.38 Å. Bi3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.12–2.14 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two equivalent Y3+, and two Cu2+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two equivalent Y3+, and two Cu2+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Cu2+, and one Bi3+ atom. In the fourth O2- site, O2- is bonded to four Sr2+, one Cu2+, and one Pb2+ atom to form distorted corner-sharing OSr4CuPb octahedra. The corner-sharing octahedral tilt angles are 20°. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Sr2+, one Pb2+, and one Bi3+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Pb2+, and one Bi3+ atom. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two equivalent Y3+, and two Cu2+ atoms. In the eighth O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two equivalent Y3+, and two Cu2+ atoms.