Antiferromagnetic quantum phase transition near x = 1.00 in NiS2-xSex system

作者：Yang Jin Hu^*; Wang Hang Dong; Du Jian Hua; Zhang Zhu Jun; Fang Ming Hu

来源：Acta Physica Sinica, 2008, 57(4): 2409-2414.

• quantum phase transition
• antiferromagnetic spin fluctuation
• NiS2-xSex system

There may bean antiferromagnetic quantum phase transition near x = 1.00 in NiS2-xSex system. The polycrystalline samples of NiS2-x Se-x (x = 0.96, 0.98, 1.00, 1.05, 1.10 and 1.20) were prepared by the solid state reaction method, and the measurements of their structure, magnetization and resistivity were carried out. It is found that the temperature dependence of susceptibility is typical characteristic of a strongly correlated electron system. Similar to high T-c superconductors, the relationship between resistivity and temperature displays a linear behavior in a wide temperature range from 50 to 300 K. For NiS2-xSex (x = 0.98 and 1.00) samples, its to T) is proportional to T-3/2 at lower temperatures (3-30 K), which shows a non-Fermi-liquid behavior. But for NiS2-x Se-x (x = 10 and 1.20) samples, its rho (T) is proooportional to T-2 at lower temperatures (3-30 K), which shown the Fermi-liquid behavior. The antiferromagnetic quantum spin fluctuation related to quantum phase transition is discussed in detail.

• 出版日期2008-4
• 单位浙江大学