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A-site ordered perovskite CaCu sub(3) Cu sub(2) Ir sub(2) O sub(12-[delta]) with square-planar and octahedral coordinated Cu ions
A novel CaCu sub(3) Cu sub(2) Ir sub(2) O sub(12-[delta]) polycrystalline sample was synthesized at 8 GPa and 1373 K. Rietveld structural analysis shows that this compound crystallizes in an -AA' sub(3) B sub(4) O sub(12)-type A-site ordered perovskite structure with space group Im-3. X-ray abs...
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Published in: | Chinese physics B 2016-02, Vol.25 (2) |
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Main Authors: | , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Online Access: | Get full text |
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Summary: | A novel CaCu sub(3) Cu sub(2) Ir sub(2) O sub(12-[delta]) polycrystalline sample was synthesized at 8 GPa and 1373 K. Rietveld structural analysis shows that this compound crystallizes in an -AA' sub(3) B sub(4) O sub(12)-type A-site ordered perovskite structure with space group Im-3. X-ray absorption spectra reveal a +2-charge state for both the square-planar and octahedral coordinated Cu ions, and the valence state of Ir is found to be about +5. Although the A-site Ca and the A'-site Cu super(2+) are 1:3 ordered at fixed atomic positions, the distribution of B-site Cu super(2+) and Ir super(5+) is disorderly. As a result, no long-range magnetic ordering is observed at temperatures down to 2 K. Electrical transport and heat capacity measurements demonstrate itinerant electronic behavior. The crystal structure is stable with pressure up to 35.7 GPa at room temperature. |
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ISSN: | 1674-1056 1741-4199 |
DOI: | 10.1088/1674-1056/25/2/020701 |