Magnetism of the rhombohedral structure Fe2 (OH)3 Cl [β -Fe2(OH)3 Cl], a member of the geometric frustration series M2(OH)3 X where the magnetic ions form a deformed pyrochlore lattice, was studied using dc and ac susceptibilities, heat-capacity, neutron powder-diffraction, and muon spin relaxation (μSR) measurements. Antiferromagnetic transition was observed at TN =9.0 K with a much larger Curie-Weiss temperature θw of approximately -64 K, suggesting that Fe2 (OH)3 Cl is a geometrically frustrated magnet. Neutron-diffraction studies revealed the transition into a long-range antiferromagnetic order below TN =9.0 K with the Fe2 + spins on the triangular lattice planes disordered, and the other ones on the kagome lattice planes having frozen moments of less than 70% of the full Fe2+ moment. Spin fluctuations below TN were verified further using μSR studies. The magnetically phase-separated feature and the spin fluctuation coexisting with a long-range magnetic order are considered to be of great interest for studying geometric frustration and the behavior of S=2 spin systems on prochlore and kagome lattices.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jul 26 2010|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics