Lesson plan
Local structure
The local structure is a term in nuclear spectroscopy that refers to the structure of the nearest neighbours around an atom in crystals and molecules. E.g. in crystals the atoms order in a regular fashion on wide ranges to form even gigantic highly ordered crystals (Naica Mine). However, in reality, crystals are never perfect and have impurities or defects, which means that a foreign atom resides on a lattice site or in between lattice sites (interstitials). These small defects and impurities cannot be seen by methods such as X-ray diffraction or neutron diffraction, because these methods average in their nature of measurement over a large number of atoms and thus are insensitive to effects in local structure. Methods in nuclear spectroscopy use specific nuclei as probe. The nucleus of an atom is about 10,000 to 150,000 times smaller than the atom itself. It experiences the electric fields created by the atom's electrons that surround the nucleus. In addition, the electric fields created by neighbouring atoms also influence the fields that the nucleus experiences. The interactions between the nucleus and these fields are called hyperfine interactions that influence the nucleus' properties. The nucleus therefore becomes very sensitive to small changes in its hyperfine structure, which can be measured by methods of nuclear spectroscopy, such as e.g.…
Article summary
The local structure is a term in nuclear spectroscopy that refers to the structure of the nearest neighbours around an atom in crystals and molecules. E.g. in crystals the atoms order in a regular fashion on wide ranges to form even gigantic highly ordered crystals (Naica Mine). However, in reality, crystals are never perfect and have impurities or defects, which means that a foreign atom resides on a lattice site or in between lattice sites (interstitials). These small defects and impurities cannot be seen by methods such as X-ray diffraction or neutron diffraction, because these methods average in their nature of measurement over a large number of atoms and thus are insensitive to effects in local structure. Methods in nuclear spectroscopy use specific nuclei as probe. The nucleus of an atom is about 10,000 to 150,000 times smaller than the atom itself. It experiences the electric fields created by the atom's electrons that surround the nucleus. In addition, the electric fields created by neighbouring atoms also influence the fields that the nucleus experiences. The interactions between the nucleus and these fields are called hyperfine interactions that influence the nucleus' properties. The nucleus therefore becomes very sensitive to small changes in its hyperfine structure, which can be measured by methods of nuclear spectroscopy, such as e.g.…
Key claims
No claims recorded.
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
No sources recorded.
Key claims and bibliography are generated from the same tracked claims and sources as the article page.