In this two-part article, we propose elastic models of disordered alloys to study the statistical properties of the random displacement and stress fields emerging from the random distributions of atoms of different sizes. In Part I, we presented real- and Fourier-space approaches enabling to obtain the amplitude of the fluctuations through the mean square displacements and stresses. In the present Part II, we extend the Fourier approach to address spatial correlations. We show that, even if the alloy is fully disordered and elastically isotropic, correlations are highly anisotropic. Our continuum predictions are validated by comparisons with atomistic models of random alloys. We also discuss the consequence of displacement correlations on finite size effects in atomistic calculations and on diffuse X-ray and neutron scattering experiments and the possible implications of stress correlations on dislocation behavior.

在这一由两部分组成的文章中，我们提出了无序合金的弹性模型，以研究不同尺寸原子的随机分布产生的随机位移和应力场的统计特性。在第一部分中，我们介绍了实空间和傅立叶空间方法，该方法能够通过均方位移和应力获得波动幅度。在当前的第二部分中，我们扩展了傅里叶方法来解决空间相关性。我们表明，即使合金是完全无序且弹性各向同性的，相关性也是高度各向异性的。通过与无规合金的原子模型进行比较，验证了我们的连续体预测。