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This article is cited in 4 scientific papers (total in 4 papers)
Phase transitions
Cubic anisotropy created by defects of “random local anisotropy” type, and phase diagram of the $O(n)$ model
A. A. Berzina, A. I. Morozovb, A. S. Sigova a MIREA — Russian Technological University, Moscow
b Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow region
Abstract:
The expression for the cubic-type-anisotropy constant created by defects of “random local anisotropy” type is derived. It is shown that the Imry–Ma theorem stating that in space dimensions $d<$ 4 the introduction of an arbitrarily small concentration of defects of the “random local anisotropy” type in a system with continuous symmetry of the $n$-component vector order parameter ($O(n)$ model) leads to the long-range order collapse and to occurrence of a disordered state, is not true if an anisotropic distribution of the defectinduced random easy axes directions in the order parameter space creates a global anisotropy of the “easy axis” type. For a weakly anisotropic distribution of the easy axes, in space dimensions 2 $\le d<$ 4 there exists some critical defect concentration, when exceeded, the inhomogeneous Imry–Ma state can exist as an equilibrium one. At the defect concentration lower than the critical one the long-range order takes place in the system. For a strongly anisotropic distribution of the easy axes, the Imry–Ma state is suppressed completely and the long-range order state takes place at any defect concentration.
Received: 23.05.2017
Citation:
A. A. Berzin, A. I. Morozov, A. S. Sigov, “Cubic anisotropy created by defects of “random local anisotropy” type, and phase diagram of the $O(n)$ model”, Fizika Tverdogo Tela, 59:12 (2017), 2420–2424; Phys. Solid State, 59:12 (2017), 2448–2452
Linking options:
https://www.mathnet.ru/eng/ftt9370 https://www.mathnet.ru/eng/ftt/v59/i12/p2420
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