Cited by 1.1k
University of Aberdeen
ORCID: 0000-0003-2253-4866Publishes on Crystal structures of chemical compounds, X-ray Diffraction in Crystallography, Crystallization and Solubility Studies. 1.2k papers and 12k citations.
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Two approaches to the synthesis and structure determination of NaZnPO4·H2O, a new open-framework, chiral, hydrated sodium zincophosphate phase, are reported. The ordered, alternating, vertex-sharing ZnO4 and PO4 groups in NaZnPO4·H2O form a new framework topology, which includes novel 4-ring “squares” and edge-sharing helixes of 4-rings. The disordered extra-framework species (Na+, H2O) are located in pear-shaped cavities (12-ring diameter), interconnected through 8-rings and 6-rings. Crystal data: NaZnPO4·H2O (I), Mr = 201.36, hexagonal, space group P6122 (No. 178), a = 10.4797(8) Å, c = 15.089(2) Å, V = 1435 Å3, Z = 12, R = 5.99%, Rw = 5.29% (709 observed reflections with I > 3σ(I). NaZnPO4·H2O (II), Mr = 201.36, hexagonal, space group P6522 (No. 179), a = 10.412(2) Å, c = 15.184(2) Å, V = 1426 Å3, Z = 12, R = 6.90%, Rw = 8.10% (687 observed reflections with I > 4σ(I).
High-resolution neutron powder diffraction experiments on the superconducting compound ${\mathrm{La}}_{1.85}$${\mathrm{Ba}}_{0.15}$Cu${\mathrm{O}}_{4}$ have revealed the presence of a tetragonal-to-orthorhombic phase transition at 180 K, together with subtle, anomalous structural instabilities at lower temperatures. These experiments demonstrate a correlation between the structural anomalies and changes in the electrical resistivity.