Dynamic evidence for a 2d - 3d crossover in the Ising spin glass Fe0.35Mg0.65Br2
نویسندگان
چکیده
2014 We report on magnetic dynamic properties in the Ising spin glass Fe0.35Mg0.65Br2. The ac susceptibility curves have been deduced from direct susceptibility and Faraday rotation measurements over a wide frequency range extending from 100 kHz down to 0.05 Hz. The temperature dependence of the characteristic relaxation time cannot be fitted by either a power or an Arrhenius law over the whole frequency range. We show that this system exhibits a dimensional 2d-3d crossover when lowering the temperature. J. Phys. France 50 (1989) 3441-3445 15 DÉCEMBRE 1989,
منابع مشابه
3d Spin Glass and 2d Ferromagnetic Xy Model: a Comparison
We compare the probability distributions and Binder cumulants of the overlap in the 3D Ising spin glass with those of the magnetization in the ferromagnetic 2D XY model. We analyze similarities and diierences. Evidence for the existence of a phase transition in the spin glass model is obtained thanks to the crossing of the Binder cumulant. We show that the behavior of the XY model is fully comp...
متن کاملNumerical Study of Competing Spin-Glass and Ferromagnetic Order
Two and three dimensional random Ising models with a Gaussian distribution of couplings with variance J and non-vanishing mean value J0 are studied using the zero-temperature domain-wall renormalization group (DWRG). The DWRG trajectories in the (J0, J) plane after rescaling can be collapsed on two curves: one for J0/J > rc and other for J0/J < rc. In the first case the DWRG flows are toward th...
متن کاملStatic and dynamic evidence for a transition at Tc = 0 in the Ising spin glass Fe0.3Mg0.7Cl2
2014 The critical behaviour of the Ising spin glass Fe0.3Mg0.7Cl2 has been studied by d.c. magnetisation, a.c. susceptibility and specific heat measurements.We have extended the range of our previous a.c. susceptibility measurements down to 0.02 Hz by using a new set up which utilises the possibilities of a 16 bit analog to digital converter. The relaxation time r and the coefficients a3 and a5...
متن کاملDerivatives and inequalities for order parameters in the Ising spin glass
Identities and inequalities are proved for the order parameters, correlation functions and their derivatives of the Ising spin glass. The results serve as additional evidence that the ferromagnetic phase is composed of two regions, one with strong ferromagnetic ordering and the other with the effects of disorder dominant. The Nishimori line marks a crossover between these two regions. PACS numb...
متن کاملCrossovers in the two-dimensional Ising spin glass with ferromagnetic next-nearest-neighbour interactions
By means of extensive computer simulations we analyse in detail the twodimensional ±J Ising spin glass with ferromagnetic next-nearest-neighbour interactions. We found a crossover from ferromagnetic to ‘spin glass’-like order both from numerical simulations and analytical arguments. We also present proof of a second crossover from the ‘spin glass’ behaviour to a paramagnetic phase for the large...
متن کامل