Doping studies of the magnetic cobaltocuprate CoSr2Y2−xCexCu2O9±δ |
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Authors: | Abbie Christina Mclaughlin David Morrice |
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Institution: | a Chemistry Department, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, UK b Centre for Science at Extreme Conditions and School of Chemistry, University of Edinburgh, Kings's Buildings, West Mains Road, Edinburgh, EH9 3JZ, UK |
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Abstract: | A structural, magnetic and electronic study of the cobaltocuprate CoSr2Y2−xCexCu2O9±δ (x=0.5-0.8) has been performed. All materials crystallise in the orthorhombic Cmcm symmetry space group in which chains of corner linked CoO4 tetrahedra run parallel to the 1 1 0 direction. An antiferromagnetic transition is observed for x=0.5-0.8; TM increases with x. A change in the dimensionality of the magnetic order occurs at x=0.8 as the interchain distance increases to a critical value. There is charge transfer between the cuprate planes and cobaltate layer as Ce doping increases, so that Co3+ is partially oxidised to Co4+ with a concomitant reduction in the valence of Cu. Superconductivity is not observed in any of the samples and a crossover from Mott to Efros and Shklovskii variable range hopping behaviour is evidenced as x increases from 0.5 to 0.8. |
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Keywords: | Antiferromagnetism Superconductivity RuSr2GdCu2O8 Triple perovskite Spin glass |
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