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Near-Surface Long-Range Order at the Ordinary Transition

Uwe Ritschel·Peter Czerner
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Abstract

We study the spatial dependence of the order parameter near surfaces belonging to the universality class of the ordinary transition. Special attention is paid to the influence of a small surface magnetic field h_1 at and above the bulk critical temperature. A detailed scaling analysis (which is confirmed by a perturbative calculation) reveals that h_1 may give rise to an anomalous short-distance behavior of the order parameter. Close to the surface the magnetization increases with a power law m\sim z^{\,κ} with κ=1-η_{\perp}^{ord} \simeq 0.23 for the three-dimensional Ising model. These results are closely related to experimental findings where exponents of the ordinary transition were observed in Fe_3 Al, while superstructure reflections revealed the existence of long-range order near the surface [X. Mailänder et al., Phys. Rev. Lett. {\bf 64}, 2527 (1990)].

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Uwe Ritschel, Peter Czerner. 1996-03-02. Near-Surface Long-Range Order at the Ordinary Transition. https://doi.org/10.1103/physrevlett.77.3645

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