What is Superconductivity?
Superconductivity is a phenomenon in which materials lose all electrical resistance when cooled below a critical temperature This is a technological breakthrough, because it allows for the production of electric currents without any losses due to resistance. The term is derived from the combination of two words: “super”, meaning “excessive”, and “conduct”, referring to electrical conduction. It was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes, who found that the electrical resistivity of mercury decreases drastically when cooled to 4.2K (or -269°C).
The phenomenon is described by the “Ginzburg-Landau” theory, which states that a new type of order arises in the electron system when cooling occurs. This order leads to a decrease in electrical resistance, and thus results in superconductivity. In traditional materials, the current carrying electrons interact with the atoms in the lattice, causing resistive losses. However, in superconductors, this interaction is suppressed. This can be achieved by decreasing the temperature of the material, which depresses the thermal vibrations of the atomic lattice and reduces the resistivity to effectively zero. In other words, superconductivity occurs when the temperature is low enough for the atoms in the material to form a superconducting Cooper pair.
The most common materials used to achieve superconductivity are those made of metals, binary compounds (e.g., lead-tin alloys), and oxides (e.g., YBa2Cu3O7). Superconductivity has been used in various applications, such as medical imaging, particle accelerators, magnetic refrigerators, and power transmission. Here are the five best examples of its application:
1. Magnetic Resonance Imaging (MRI): MRI technology uses superconducting magnets to create strong, non-invasive magnetic fields. The interaction of these fields with the body’s atomic structures can create an image of the body’s internal structures, enabling medical professionals to make accurate diagnoses.
2. Superconducting Magnet Levitation (Maglev): Maglev is a type of high-speed transportation that uses superconducting magnets to levitate and move vehicles along a guideway. It is extremely fast and efficient, reducing traveling time and costs compared to traditional forms of transportation.
3. Particle Accelerators: Particle accelerators use superconducting magnets to accelerate particles, such as electrons and protons, to extremely high speeds. These particles are then collided together, enabling scientists to study the behavior of matter at the subatomic level.
4. Magnetic Refrigerators: Superconducting magnets are used in magnetic refrigerators to create cold temperatures without the use of chemicals or mechanical moving parts. This type of refrigerator is extremely efficient, and can be used for applications such as cooling data centers and food storage.
5. High-temperature Superconductors (HTS): High-temperature superconductors, or HTS, are materials that can be cooled to a temperature of up to -135°C without losing resistance. This makes them more practical for a wider range of applications than traditional superconductors, such as power transmission, electric motors, and MRI scanners.
In conclusion, superconductivity is a phenomenon that occurs when materials cool to extremely low temperatures and lose all electrical resistance. It has proven to be a revolutionary breakthrough in science and technology, thanks to its numerous applications ranging from medical imaging to transportation. This article has explored five of the best examples of its application, including Magnetic Resonance Imaging, Maglev trains, particle accelerators, magnetic refrigerators, and high-temperature superconductors.