M. Nishiyama et al., MAGNETIC-PROPERTIES OF KAGOME LATTICE ANTIFERROMAGNETS, RFE(3)(OH)(6)(SO4)(2) [R=NH4,NA], Czechoslovak journal of Physics, 46, 1996, pp. 2053-2054
An antiferromagnet on a Kagome lattice is a strongly frustrated spin s
ystem. In hexagonal compounds RFe(3)(OH)(6)(SO4)(2) [R=NH4, Na], Fe3ions form the Kagome lattice in the c-plane with the antiferromagnetic
interaction. Successive phase transitions were found around 60 K by m
eans of susceptibility and NMR measurements. The temperature range of
the intermediate phase is about 5 K. NMR spectra of H-1 and Na-23 have
structures and give information about the magnetic structures in each
phase.