Critical and tricritical behavior of a selectively diluted triangular Ising antiferromagnet in a field |
| |
Authors: | M Borovský M ŽukovičA Bobák |
| |
Institution: | Department of Theoretical Physics and Astrophysics, Faculty of Science, P.J. Šafárik University, Park Angelinum 9, 041 54 Košice, Slovak Republic |
| |
Abstract: | We study a geometrically frustrated triangular Ising antiferromagnet in an external magnetic field which is selectively diluted with nonmagnetic impurities employing an effective-field theory with correlations and Monte Carlo simulations. We focus on the frustration-relieving effects of such a selective dilution on the phase diagram and find that it can lead to rather intricate phase diagrams in the dilution-field parameters space. In particular, in a highly (weakly) diluted system the frustration is greatly (little) relieved and such a system is found to display only the second(first)-order phase transitions at any field. On the other hand, for a wide interval of intermediate dilution values the transition remains second-order at low fields but it changes to first-order at higher fields and the system displays a tricritical behavior. The existence of the first-order transition in the region of intermediate dilution and high fields is verified by Monte Carlo simulations. |
| |
Keywords: | Triangular Ising antiferromagnet Frustration Effective-field theory Selective dilution Phase transition Tricritical point |
本文献已被 ScienceDirect 等数据库收录! |