Magnetization of staggered S 1 2 antiferromagnetic Heisenberg chain systems

The molecule based S 1 2 antiferromagnetic Heisenberg chain systems Cu Pyrimidine Cu C4N2H4 NO3 2 H2O 2 and Cu Benzoate Cu C6H5COO 2 3H2O, because of the Dzyaloshinskii Moriya interaction and a staggering of the g tensor, are characterized by a magnetic principal axis system a amp; 8242; amp; 8242;bc amp; 8242; amp; 8242; distinct from the crystallographic unit cell. Along a amp; 8242; amp; 8242; a behavior corresponding to the uniform S 1 2 antiferromagnetic Heisenberg chain occurs, while along c amp; 8242; amp; 8242; the effect of g tensor staggering and Dzyaloshinskii Moriya interaction are most prominent. Here, we discuss the field and temperature dependent magnetization along a amp; 8242; amp; 8242; and c amp; 8242; amp; 8242; of these systems, in particular with respect to the relevance of the inhomogeneity parameter k controlling the ratio between longitudinal and transverse magnetization component