Low Temperature Physics: 28, 551 (2002); https://doi.org/10.1063/1.1496666 (5 pages)
Физика Низких Температур: Том 28, Выпуск 7 (Июль 2002), c. 768-773 ( к оглавлению , назад )
Specific heat study of magnetic excitations in a one-dimensional S =1 Heisenberg magnet with strong planar anisotropy
A. Feher, M. Orendáč, A. Orendáčová, and E. Čižmár
Department of Experimental Physics, Faculty of Science, P.J.Šafárik University, Park Angelinum 9, 04154 Košice, Slovakia
Received February 14, 2002
The results of experimental studies of the specific heat of the magnetic chain compounds Ni(C2H8N2)2Ni(CN)4, Ni(C11H10N2O)2Ni(CN)4, and Ni(C10H8N2)2Ni(CN)4×H2O are reported. All compounds are identified as S = 1 planar Heisenberg magnetic chains with large planar anisotropy and different values of the in-plane anisotropy constant. The low-temperature specific heat data are interpreted assuming the existence of noninteracting excitons and antiexcitons as elementary excitations from the singlet-ground state. The extended
strong-coupling model is used for analysis of the data at higher temperatures. The applicability of the models used with respect to the value of the in-plane anisotropy is discussed.