Novel S=3/2 Triangular Antiferromagnet Ag2CrO2 with Metallic Conductivity

作者：Yoshida Hiroyuki^*; Takayama Muromachi Eiji; Isobe Masaaki

来源：Journal of the Physical Society of Japan, 2011, 80(12): 123703.

DOI：10.1143/JPSJ.80.123703

• Ag2CrO2
• frustration
• triangular lattice
• Heisenberg spin
• RKKY interaction

A novel metallic silver chromate, Ag2CrO2, was synthesized using a high-pressure technique. Ag2CrO2 crystallizes in trigonal symmetry with lattice parameters of a = 2.9271(1) angstrom and c = 8.6721(4) angstrom. The structure consists of CrO2 and double Ag layers stacked alternately along the c-axis. The former realizes an S = 3/2 triangular-lattice Heisenberg system, while the latter provides itinerant electrons. Ag2CrO2 exhibits an antiferromagnetic long-range order at T-N = 24K with the weak ferromagnetic moment. The resistivity shows a sudden drop at T-N, suggesting a large s-d interaction (RKKY interaction) between the Cr 3d localized spins on the triangular lattice and the Ag 5s itinerant electrons. The RKKY interaction is responsible for releasing the magnetic frustration and the three-dimensional long-range ordering at T-N.

• 出版日期2011-12