Introduction to amorphous materials1

Introduction to Amorphous Materials

With the development of human technology and technology, a new type of amorphous crystalline material has emerged, including amorphous alloys, amorphous conductors, amorphous superconductors, amorphous superconductors and organic polymer glasses. So what exactly is an amorphous material, let me give you a brief introduction to the concept and some characteristics. So-called amorphous materials, also called amorphous or glassy materials, are rigid solids with high hardness and high viscosity comparable to crystalline materials. Due to his composing courtyard, the spatial arrangement of molecules is not periodic and translational symmetry leads to the destruction of the long-term program of his crystalline state. It is only by the mutual correlation between atoms that he has a short program in a small area of ​​the atom or molecule. But so far there is no way to determine the atomic structure of amorphous materials.

Let's talk about the basic characteristics of amorphous materials.

Firstly, because it does not have any long programs, but only short programs between cells, its wave vector K is no longer a good quantum number to describe the state of motion.

Second his electron diffraction. The neutron diffraction and X-ray diffraction patterns are composed of relatively wide halos and diffuse rings, so that she cannot see any diffraction contrast formed by crystal boundaries and crystal defects under the electron microscope.

Third, any amorphous material is in a metastable state. When the surrounding temperature continues to rise, there will be obvious structural changes in a narrow temperature range, making it change from amorphous to static. The crystallization process depends on the atomic diffusion coefficient, interface energy and dissolution entropy of the material.

The above are just the general material properties of amorphous materials. In more different materials, they also have some special properties of their own.