Y. Todate et al., SPIN CORRELATIONS IN THE TRIANGULAR-LATTICE RANDOM MIXED ANTIFERROMAGNET, Journal of physics. Condensed matter, 10(18), 1998, pp. 4057-4070
Spin-glass-like freezing in the triangular-lattice random mixed antife
rromagnet YFeMnO4 has been analysed by Monte Carlo simulation. Experim
ental results on random diluted LuGaMnO4 have also been presented. The
analysis provides a qualitative interpretation of the experimentally
observed spin freezing in the random mixed system YFeMnO4 as well as t
he diluted systems LuGaMnO4 and LuFeMgO4. The non-uniform antiferromag
netic interaction due to the random distribution of Mn2+ and Fe3+ in Y
FeMnO4 prevents long-range spin ordering, but instead it causes well-d
efined short-range correlation and a distribution of the relaxation ti
me. The simulation demonstrates the formation of a higher-order struct
ure of the short-range correlation at low temperatures. The developmen
t of a long-range correlation of quasi-static spins at the cusp temper
ature of the susceptibility is discussed.