A. Furrer and H.-U. Güdel
Spin-wave excitations in finite chain segments in the diluted one-dimensional Heisenberg antiferromagnet CsMn_1-xMg_xBr₃
Eur. Phys. J. B 16, 81-84 (2000)                 

Abstract: The inelastic neutron scattering technique was employed to study the magnetic excitation spectra in the diluted one-dimensional Heisenberg antiferromagnet CsMn_1-xMg_xBr₃ (x=0, 0.05, 0.10, 0.25, 0.50). The spectral response is interpreted in terms of spin-wave excitations in finite chain segments of Mn²⁺ ions, which are found to exist as long as the chain length exceeds twice the wavelength of the spin excitation. This limit determines the crossover into the mesoscopic regime.