TITLE:
Ferro- and Antiferromagnetic Aspects of Alternating Spin Systems
AUTHORS:
Aiman Al-Omari
KEYWORDS:
Spin Wave Theory, Alternating Spins, Specific Heat, Schottky Peak, Susceptibility
JOURNAL NAME:
World Journal of Condensed Matter Physics,
Vol.1 No.4,
November
28,
2011
ABSTRACT: Using linear spin-wave theory we have investigated the thermal properties of frustrated dimerized Heisenberg ferri- magnetic system with alternating spins and on one- and two-dimensional lattices. At intermediate temperature the susceptibility and the specific heat shows a minimum and a Schottky-like peak respectively. Frustration enhances the antiferromagnetic aspect in the system by causing a left-shift in the peak and the minimum which indicates that the antiferromagnetic behavior overbalance the ferromagnetic one at earlier temperatures. The effect of dimerization is different for the two form of the coupling constants. While the expanded form; , boosts the antiferro- magnetic behavior of the system by making a left-shift of the peak and the minimum, the distance-variable coupling
constant; shifts them to the right opposing, for a while, the appearance of the antiferromagnetic aspect. The slope of after the minimum shows that the aspect of ferrimagnetic system with spins (3/2, 1) is more antiferromagnetic and the system with (3/2, 1/2) is ferromagnetic. Free energy and magnetization decreased by increasing dimerization as well as frustration. Both of them scales with PACS numbers: 75.10.Jm, 75.50.Ge.