Structural Study of the Quantum-Spin Chain Compound (VO)2P2O7

✍ Scribed by Z. Hiroi; M. Azuma; Y. Fujishiro; T. Saito; M. Takano; F. Izumi; T. Kamiyama; T. Ikeda

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 675 KB
• Volume: 146
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8364

✦ Synopsis

The crystal structure of the quantum-spin chain compound (VO) 2 P 2 O 7 was studied by electron, X-ray, and neutron di4raction. A polycrystalline sample which clearly exhibited a singlet ground state in magnetic susceptibility measurements was examined. Electron di4raction experiments revealed systematic extinctions which are consistent with an orthorhombic space group Pca2 1 , in good agreement with previous studies. However, the recent single-crystal X-ray analysis by Nguyen et al. concluded that it is monoclinic with space group P2 1 . This discrepancy may imply that (VO) 2 P 2 O 7 crystallizes in two slightly di4erent structures depending on preparation conditions. The structural parameters of orthorhombic (VO) 2 P 2 O 7 were de5ned by Rietveld analyses of X-ray and neutron powder di4raction data; a ‫؍‬ 7.73808(7) A s , b ‫؍‬ 9.58698(8) A s , c ‫؍‬ 16.5895(1) A s , and Z ‫؍‬ 8. Crystallographic disorder was also studied by high-resolution electron microscopy and discussed in terms of positional disorder in the arrangement of the P 2 O 7 groups.