Synthesis, structural and magnetic properties of the solid solution (CuCl1-xBrx)LaNb2O7 (0 < x < 1)

Yoshihiro Tsujimoto, Atsushi Kitada, Hiroshi Kageyama, Masakazu Nishi, Yasuo Narumi, Koichi Kindo, Yoko Kiuchi, Yutaka Ueda, Yasutomo J. Uemura, Yoshitami Ajiro, Kazuyoshi Yoshimura

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


The two-dimensional (2D) quantum spin system (CuCl)LaNb2O 7 has a spin-singlet ground state with a gap of 2.3 meV, while the isostructural material (CuBr)LaNb2O7 displays a collinear antiferromagnetic order at TN = 32 K. Here, we report on the synthesis of solid solution (CuCl1-xBrx)LaNb 2O7 (0 < x < 1), and its structural and magnetic properties investigated by magnetic susceptibility, high-field magnetization, and neutron diffraction measurements. The x dependences of cell parameters follow Vegard's law, verifying the uniform distribution of Cl and Br atoms at the halide site, although a more complex structural evolution is inferred from an opposing correlation between the intra- and interlayer cell distances (vs x). 5%-Br substitution is found to induce an antiferromagnetic order with T N = 7 K, consistent with recent μSR results, and the magnetic structure is collinear, having a significantly reduced moment. Further Br substitution leads to a linear increase in TN up to x = 1. These results indicate that (CuCl)LaNb2O7 is located in the vicinity of the quantum phase boundary.

Original languageEnglish
Article number014709
Journaljournal of the physical society of japan
Issue number1
Publication statusPublished - 2010 Jan
Externally publishedYes


  • (CuBr)LaNbO
  • (CuCl)LaNbO
  • Magnetization
  • Neutron diffraction
  • Quantum spin system
  • Spin gap
  • Susceptibility

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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