Structural studies of SrTcO3, CaTcO3, and Pb2Tc2O7-d

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International Union of Crystallography
Little is known regarding the structure and properties of technetium oxides. This is mainly due to the absence of any naturally occurring Tc isotopes and the radioactivity of those available [1]. Tc oxides are important since 99Tc is found in nuclear waste and has a long half-life (2.13 × 105 yr). Tc is a 4d element, and like its lighter analogue Mn a 3d element it can adopt a number of oxidation states. 3d oxides are generally, but not always magnetic, while 4d and 5d oxides, with their more spatially extended d-orbitals tend not to be magnetic although SrRuO3 [2] is a notable exception. Here we have combined synchrotron X-ray and neutron diffraction to examine the structure of CaTcO3, SrTcO3 and Pb2Tc2O7-d. The only previous report on these materials was by Muller, White and Roy in 1964 [3]. They reported the existence of these materials and suggested the CaTcO3 and SrTcO3 were orthorhombic whereas the Pb2Tc2O7-d was reported as being pyrochlore. This earlier work concentrated on syn-thesis hence little is known about these three compounds and there has been no study of their structures or magnetic properties. © International Union of Crystallography
Technetium oxides, Valence, Pyrochlore, Orthorhombic lattices, Technetium compounds, Magnetic properties
Thorogood, G. J., Kennedy, B. J., Avdeev, M., Ting, J., Zhang, Z., & Carter, M. L. (2011). Structural studies of SrTcO3, CaTcO3, and Pb2Tc2O7-d. Poster presented at XXII IUCr Congress, Madrid, Spain, 22-30 August 2011. In Acta Crystallographica Section A: Foundations and Advances, A67, C603-C604. doi:10.1107/S0108767311084716