Abstract
A high-field magnetization process for the triangular spin prism Na17[Mn6(H2O)2(AsW9O34)2(AsW6O26)]·38H2O, which consists of six Mn2+ ions (S=5⁄2), has been investigated. The magnetization at low temperature shows a 1/3 plateau around 5.5 T. It is examined by theoretical calculations using exact diagonalization. The experimental results can be reproduced, but only in a restricted parameter range. It implies that the plateau originates from a delicate balance of exchange couplings. We propose that the plateau is stabilized by some external perturbations, such as thermal/quantum fluctuations.
