👉 Polycrystalline is a type of crystalline material in which each crystal has its own unique, distinct structure and composition. It is made up of multiple layers of atoms or molecules that are arranged in such a way that they can be separated by different amounts of energy and pressure. In the context of crystals, polycrystalline materials are typically composed of two or more types of crystalline materials, each with its own unique properties. These materials can have different crystal structures,