The NQR Observation of Spin-Peierls Transition in an Antiferromagnetic MX-Chain Complex [NiBr(chxn)2]Br2

• Published in: Journal of the American Chemical Society Vol. 126; no. 6; pp. 1614 - 1615
• Main Authors: Takaishi, Shinya, Tobu, Yasuhiro, Kitagawa, Hiroshi, Goto, Atsushi, Shimizu, Tadashi, Okubo, Takashi, Mitani, Tadaoki, Ikeda, Ryuichi
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 18.02.2004
• Subjects: Antiferromagnetics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Physics; Studies of specific magnetic materials; Transition elements Complexes; Temperature dependence; Spin-Peierls transition; Nickel Complexes; Electron lattice interaction; Antiferromagnetic materials; Nuclear quadrupole resonance; Organic ligand; Bromo complex; Experimental study; Magnetic transitions
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja039857x

81Br Nuclear quadrupole resonance (NQR) measurement was performed in an S = 1/2 one-dimensional Heisenberg antiferromagnetic metal complex [NiBr(chxn)2]Br2 (chxn:  1R,2R-diaminocyclohexane), having a halogen-bridged MX chain structure −Br−Ni3+−Br−Ni3+−Br−. Two 81Br NQR signals were observed below 40 K, while a single signal was observed above 130 K, showing the presence of two nonequivalent bridging Br sites below 40 K. This NQR result together with previously reported magnetic susceptibility and X-ray results indicate the occurrence of a transition into a spin-Peierls state between 40 and 130 K. This communication reports the first spin-Peierls transition in metal complexes in which pure d electrons contribute to the magnetism. In addition, we demonstrated a new experimental method for studying a spin-Peierls system.