中国物理B ›› 2008, Vol. 17 ›› Issue (9): 3490-3494.doi: 10.1088/1674-1056/17/9/058

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Effect of magnetic field on the spin-Peierls transition in single-crystal CuGeO

王洪涛1, 王清波2, 徐象繁2, 陶前2, 许祝安2   

  1. (1)Department of Physics and Information Science, Wenzhou University, Wenzhou 325027, China; (2)Department of Physics, Zhejiang University, Hangzhou 310027, China
  • 收稿日期:2008-01-03 修回日期:2008-02-05 出版日期:2008-09-08 发布日期:2008-09-08
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10634030) and the Zhejiang Province Natural Science Foundation of China (Grant No Y605106).

Effect of magnetic field on the spin-Peierls transition in single-crystal CuGeO

Wang Qing-Bo(王清波)a), Xu Xiang-Fan(徐象繁)a), Tao Qian(陶前)a), Wang Hong-Tao(王洪涛)b), and Xu Zhu-An(许祝安)a)†   

  1. a Department of Physics, Zhejiang University, Hangzhou 310027, China; b Department of Physics and Information Science, Wenzhou University, Wenzhou 325027, China
  • Received:2008-01-03 Revised:2008-02-05 Online:2008-09-08 Published:2008-09-08
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10634030) and the Zhejiang Province Natural Science Foundation of China (Grant No Y605106).

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摘要： This paper reports that high quality CuGeO$_{3}$ single crystals were successfully grown by floating-zone technique and the magnetic property was studied. The temperature dependence of magnetic susceptibility below the spin-Peierls (SP) transition temperature ($T_{\rm sp})$ under magnetic fields applying along both the $a$- and $c$-axis direction can be fitted well by a model of noninteracting dimmers. The spin gap derived from the fitting is consistent with other reports. There is a very weak anisotropy in the fitting parameters for different directions, which should be expected from a SP system. A small upturn in susceptibility at low temperature due to paramagnetic impurities and/or defects can be observed. A suppression of the upturn by magnetic field is first discovered in this system and the possible origins for this suppression are discussed.

Abstract: This paper reports that high quality CuGeO$_{3}$ single crystals were successfully grown by floating-zone technique and the magnetic property was studied. The temperature dependence of magnetic susceptibility below the spin-Peierls (SP) transition temperature ($T_{\rm sp})$ under magnetic fields applying along both the $a$- and $c$-axis direction can be fitted well by a model of noninteracting dimmers. The spin gap derived from the fitting is consistent with other reports. There is a very weak anisotropy in the fitting parameters for different directions, which should be expected from a SP system. A small upturn in susceptibility at low temperature due to paramagnetic impurities and/or defects can be observed. A suppression of the upturn by magnetic field is first discovered in this system and the possible origins for this suppression are discussed.

Key words: spin chain, spin--Peierls transition, spin dimmer, magnetic susceptibility

中图分类号:  (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.))

  • 75.30.Kz
75.20.Ck (Nonmetals) 75.30.Cr (Saturation moments and magnetic susceptibilities) 75.30.Gw (Magnetic anisotropy) 75.40.Cx (Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)) 81.10.Fq (Growth from melts; zone melting and refining)