Final answer:
X-ray crystallography is a method used to determine the atomic and molecular structure of a crystal by diffracting X-rays through it. It provides essential details on atom size, shape, and arrangement within the crystal. This technique has been pivotal in the study of DNA and high-temperature superconductors.
Step-by-step explanation:
X-ray crystallography is a technique that involves the diffraction of X-rays by a crystal to determine the size of the unit cell and the arrangement of atoms within the crystal. The diffraction pattern produced, as shown in figures like 13.3.1 or 30.27, provides valuable information about crystal structure. This method was famously used by Rosalind Franklin in the research that contributed to Watson and Crick's discovery of DNA's structure. X-ray crystallography is not only essential for confirming the size and shape of atoms but also for revealing the atomic arrangements in materials, which is critical in research like that of high-temperature superconductors. These superconductors have complex lattice arrangements that are crucial for their superconducting properties, and their study relies heavily on x-ray diffraction techniques.
Diffraction is a phenomenon where an electromagnetic wave changes direction upon encountering a barrier similar in size to its wavelength. Since X-rays have wavelengths on the order of a few angstroms, comparable to the distance between neighboring atoms in a crystal, they are an ideal probe for studying crystal structures.