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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 4 Issue 4 (1998) pp 431-440
Phase transition in the Blume-Capel model with second neighbour interaction
M. Badehdah (1), S. Bekhechi (1), A. Benyoussef (1) (a), M. Touzani (1)(2)
(1) Laboratoire de Magnétisme et de Physique des Hautes Énergies, Département de Physique, BP 1014, Faculté des Sciences, Rabat, Morocco
(2) Laboratoire des Matériaux, des Sciences et Techniques des Énergies Renouvelables, BP 6207, ENSET, Rabat, Morocco
Received: 3 November 1997 / Revised: 31 March 1998 / Accepted: 7 April 1998
Abstract: A two dimensional antiferromagnetic spin-1 Ising model with negative next- nearest neighbour interaction (J2<0) and under an external magnetic field is investigated by two methods: The mean-field theory and Finite-Size-Scaling based on transfer matrix (TMFSS) calculations. The ground state diagrams exhibit several new phases including frustrated ones. At finite temperature we obtain by these two methods quite rich phase diagrams, with several multicritical points. While Mean field approximation yields phase diagrams which are sometimes even qualitatively incorrect, accurate results are obtained from transfer matrix finite size scaling calculations. For a certain range of interaction parameters, the model is shown to violate the ordinary universality hypothesis.
PACS. 75.10 Hk Classical spin models
(a) email: benyous@fsr.ac.ma
Article in PDF-Format (313 KB)
Online publication: August 27, 1998
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