Nuclear-Magnetic-Resonance Properties of the Staircase Kagomé Antiferromagnet $PbCu_3TeO_7$
DAI Jia1, WANG Peng-Shuai1, SUN Shan-Shan1, PANG Fei1, ZHANG Jin-Shan2, DONG Xiao-Li3, YUE Gen3, JIN Kui3, CONG Jun-Zhuang3, Sun Yang3, YU Wei-Qiang1**
1Department of Physics, Renmin University of China, Beijing 100872 2School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing 102206 3Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190
We report the first nuclear magnetic resonance (NMR) study on single crystals of staircase Kagomé antiferromagnet PbCu3TeO7 (TN1∼36 K). A Curie constant Θ ∼−140 K is obtained by a Curie–Weiss fit to the high-temperature Knight shift of 125Te. The hyperfine coupling constant is estimated to be 125Ahf=−67 kOe/μB, and a strong interlayer coupling among staircase Kagomé planes is suggested with such a large hyperfine coupling, according to the lattice structure. The 63, 65Cu NMR spectra are found by the zero-field (ZF) NMR at T=2 K, and the internal hyperfine fields are estimated to be 10.3 T and 9.6 T, for Cu(1) and Cu(2) sites, respectively, in the lattice. A second type of ZF NMR signal with a large rf enhancement is also seen after field-cycling through a high magnetic field.
2015, Vol. 32 
