Abstract
The spin gap in Tl2Ru2O7 and the formation of haldane chains in three-dimensional crystals were analyzed. The compound formed in a cubic pyrochlore structure with the space group for Fd3m and a=10.17936 Å. When it had undergone the metal-insulator transition, the crystal structure transformed the cubic pyrochlore structures to the orthorhombic structure. A drastic drop in bulk susceptibility at the meta-insulator transition suggested that the transition should be accompanied by a strong change in spin spectrum. The metal-insulator transition in Tl 2Ru2O7 accompanied by a structural transition with the formation of a spin gap is found to be the first case of the spontaneous formation of 1D Haldane chain with the spin gap out of a 3D cubic structure.
Original language | English |
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Pages (from-to) | 471-476 |
Number of pages | 6 |
Journal | Nature Materials |
Volume | 5 |
Issue number | 6 |
DOIs | |
State | Published - Jun 10 2006 |
Externally published | Yes |
Funding
We thank the Korea Basic Science Institute for allowing us to use their high-temperature SQUID magnetometer and J. van Duijn for providing us with his HET data on Bi2Ru2O7. J.G.P. acknowledges the financial support of the CSCMR at Seoul National University, the CNRF project, the BAERI programme and the Proton Accelerator User Program (No. M102KS010001-02K1901-01810). The work of D.K. was supported by the Deutsche Forshungsgemeinschaft through SFB 608, by the European project COMEPHS and by the Leverhulme Professorship in Loughborough University and S.S. thanks the Netherlands Organization for Scientific Research (NWO 047.016.005), Russian Foundation for Basic Research (RFFI-04-02-16096), INTAS (05-109-4727) and Ural branch of Russian Academy of Science. Experiments at ISIS were supported by the Council for the Central Laboratory of the Research Councils of the UK. Correspondence and requests for materials should be addressed to J.-G.P. Supplementary Information accompanies this paper on www.nature.com/naturematerials.