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This article is cited in 9 scientific papers (total in 9 papers)
CONDENSED MATTER
Aging and memory effects in the nonequilibrium critical behavior of structurally disordered magnetic materials in the course of their evolution from the low-temperature initial state
V. V. Prudnikov, P. V. Prudnikov, E. A. Pospelov, P. N. Malyarenko Omsk State University, pr. Mira 55, Omsk, 644077, Russia
Abstract:
The Monte Carlo study of the nonequilibrium critical evolution of structurally disordered anisotropic magnetic materials from the low-temperature initial state with the reduced magnetization $m_0=1$ is performed within the broad range of spin densities, $p=1.0$, $0.95$, $0.8$, $0.6$, and $0.5$. It is shown that, in such systems, the pinning of domain walls by structural defects occurring when the evolution starts from the low-temperature state leads to significant changes in the nonequilibrium “aging” and “memory” effects in comparison to those characteristic of the “pure” system. As a result, in the long-term regime at times $t-t_w\gg t_w\gg1$, an anomalously strong slowing down in the correlation effects is revealed. It is shown that a decrease in the autocorrelation function with time occurs according to a power law typical of the critical relaxation of the magnetization in contrast to a usual scaling dependence. Eventually, the limiting value of the fluctuation-dissipation ratio X$^\infty$ for the structurally disordered systems with $p<1$ vanishes, whereas for the pure system, we have X$^\infty=0.784(5)$. The nonequilibrium critical “superaging” stage is found. This stage is characterized by the critical exponent $\mu=2.30(6)$ for weakly disordered systems and by $\mu=2.80(7)$ for the systems with strong disorder.
Received: 14.05.2015 Revised: 29.06.2015
Citation:
V. V. Prudnikov, P. V. Prudnikov, E. A. Pospelov, P. N. Malyarenko, “Aging and memory effects in the nonequilibrium critical behavior of structurally disordered magnetic materials in the course of their evolution from the low-temperature initial state”, Pis'ma v Zh. Èksper. Teoret. Fiz., 102:3 (2015), 192–201; JETP Letters, 102:3 (2015), 167–175
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https://www.mathnet.ru/eng/jetpl4698 https://www.mathnet.ru/eng/jetpl/v102/i3/p192
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Abstract page: | 224 | Full-text PDF : | 59 | References: | 35 | First page: | 17 |
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