Experimental data for the magnetic susceptibility and magnetostriction of CuGeO 3 are analyzed within a one-dimensional antiferromagnetic model with nearest (J 1 ) and next-nearest neighbour interactions (J 2 ). We show that the ratio of the exchange constants in the antiferromagnetic chains of CuGeO 3 amounts to J 2 /J 1 = 0.354(0.01), i.e. it is significantly larger than the critical value for the formation of a spontaneous gap in the magnetic excitation spectrum without lattice dimerization. The susceptibility data are reproduced by our numerical results over the temperature range from 20K to 950K to a high degree of accuracy for J 1 = 80.2(3.0) and J 2 = 28.4(1.8). The pressure dependence of the exchange constants is estimated from magnetostriction data. Furthermore, the specific heat data are checked on consistency against the calculated entropy of the above model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.