Calorimetric and spectroscopic study of quasi-one-dimensional Haldane magnets (Y1 − xNdx)2BaNiO5 (x = 1, 0.75, 0.50, 0.25)

Journal of Experimental and Theoretical Physics. 2010. Vol. 111. No. 2. P. 204–208.

Попова Е. А., Васильев А. Н., Климин С. А., Нарожный М. В., Попова М. Н.

The temperature dependences of the heat capacity and optical transmission spectra of quasi-one-dimensional Haldane magnets (Y1 − x Nd x )2BaNiO5 (x = 1, 0.75, 0.50, 0.25) have been studied. All the compounds studied undergo antiferromagnetic ordering. In the ordered state, the internal magnetic field produces splitting of the ground-state Kramers doublet of Nd3+ ion. The temperature dependences of the magnitude of splitting, as determined from spectroscopic data, were used to calculate the Schottky anomaly on the heat capacity curve. Nonequivalent centers related to neodymium ions have been found in compounds with x = 0.75, 0.50, and 0.25.

Ключевые слова: Antiferromagnetic ordering, quasi-one-dimensional magnets, Haldane chains, magnetic anisotropy