Magnetostructural tweed in ferromagnetic Heusler shape-memory alloys

In a number of ferromagnetic Heusler shape-memory alloys, magnetic modulations occur as precursors to the magnetic and/or martensitic transitions. They show up in the form of stripe-like or cross-hatched patterns. In the latter case, they correspond to the well known tweed patterns observed in numerous alloys undergoing a martensitic transition. In this work, we show that the tweed concept is not just structural but applicable to a much broader class of materials and that its origin lies in very general requirements. We present a model that fulfills these requirements and is applied to the study of magnetic stripe-like precursor modulations in ferromagnetic Heusler shape-memory alloys.