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Ruthenium(V) Oxides from Low‐Temperature Hydrothermal Synthesis
Author(s) -
Hiley Craig I.,
Lees Martin R.,
Fisher Janet M.,
Thompsett David,
Agrestini Stefano,
Smith Ronald I.,
Walton Richard I.
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201310110
Subject(s) - orthorhombic crystal system , ruthenium , antiferromagnetism , pyrochlore , hydrothermal circulation , ruthenium oxide , hydrothermal synthesis , neutron diffraction , crystallography , materials science , powder diffraction , chemistry , crystal structure , chemical engineering , phase (matter) , condensed matter physics , catalysis , physics , biochemistry , organic chemistry , engineering
Abstract Low‐temperature (200 °C) hydrothermal synthesis of the ruthenium oxides Ca 1.5 Ru 2 O 7 , SrRu 2 O 6 , and Ba 2 Ru 3 O 9 (OH) is reported. Ca 1.5 Ru 2 O 7 is a defective pyrochlore containing Ru V/VI ; SrRu 2 O 6 is a layered Ru V oxide with a PbSb 2 O 6 structure, whilst Ba 2 Ru 3 O 9 (OH) has a previously unreported structure type with orthorhombic symmetry solved from synchrotron X‐ray and neutron powder diffraction. SrRu 2 O 6 exhibits unusually high‐temperature magnetic order, with antiferromagnetism persisting to at least 500 K, and refinement using room temperature neutron powder diffraction data provides the magnetic structure. All three ruthenates are metastable and readily collapse to mixtures of other oxides upon heating in air at temperatures around 300–500 °C, suggesting they would be difficult, if not impossible, to isolate under conventional high‐temperature solid‐state synthesis conditions.