Zero thermal expansion in KxMnxIn2-x(MoO4)3 based materials

Zero thermal expansion (ZTE) materials can solve problems such as device failure and cracking caused by mismatched coefficient of thermal expansion. However, ZTE material is rare in nature. NaZr ₂(PO ₄) ₃ is a framework compound with near-zero thermal expansion due to coupled rotations of rigid ZrO ₆ and PO ₄ polyhedra in the structure, and several studies have been devoted to obtaining more ZTE compounds by chemical substitution of Na or Zr. Inspired by the AAV concept we proposed, in this work, the PO ₄ tetrahedra with a small volume has been replaced by the large volume MoO ₄ tetrahedra in K _xMn _xIn _{2- x}(MoO ₄) ₃ ( x = 0.4, 0.6, 0.8, and 1.0) compounds to provide more space for the coupling rotation of the polyhedron, and reduce the coefficient of thermal expansion. On the other hand, the flexibility of the framework structure has been modulated by the content of K ⁺ to achieve new ZTE materials, and the effects of K ⁺ content on crystal structure and thermal expansion have been analyzed in detail by combining variable temperature XRD and Raman. These findings not only provide more ZTE materials, but also suggest a promising design method for ZTE materials.