The magnetic susceptibilities, χ⁄⁄c and χ⊥c, for the field parallel and perpendicular to the chain axis are calculated exactly of an anisotropic classical Heisenberg chain diluted randomly with nonmagnetic impurities. These impurities break up completely the host chain into independent segments (finite chains) with various lengths. It is shown that the combined effect of the finite chain and the dipolar anisotropy leads to the crossover in the relative values of χ⁄⁄c and χ⊥c from χ⁄⁄c>⊥c to χ⊥c>χ⁄⁄c at sufficiently low temperatures, which has recently been observed in (CH3)4NMn1-xCdxCl3 (TMMC: Cd) and (CH3)4NMn1-xCdxCl3 (TMMC: Cu). Numerical results for the temperature dependence of χ⁄⁄c and χ⊥c of these two systems are in good quantitative agreement with the experimental data.
ASJC Scopus subject areas
- Physics and Astronomy(all)