03.10.2022

Meng strongest magnetic fields

Strong magnetic fields play an important role in data processing as well as in medical and chemical imaging techniques. Most devices are based on the magnetoresistance, or mr effect (mr = magnetoresistance). The mr effect describes the relative change of the electrical resistance of a conductor when a magnetic field is applied – and thus the specific material property.

Ultrasensitive magnetic field sensor

In the case of magnetic feedstocks, various effects such as the "giant magneto-resistive effect" (gmr), the collosal magneto-resistive effect (cmr) etc. Differentiated (cf. Fundamentals of magneto-resistive effects). The effects are known and used for a variety of applications, but nevertheless they are not yet fully explained scientifically.

In the past fifty years, scientists have succeeded in steadily increasing the intensity of the magnetic fields generated. Today it is regularly possible to produce stable magnetic fields near 10 tesla and pulsating ones at 40 tesla (1 tesla equals 10’000 gauss, cf. Magnetic units). When using these fields, it is of course important to have the most precise sensor technology possible in order to determine them accurately. There is still a lack of a general-purpose, temperature-independent, small, simple and cheap sensor for strong magnetic fields. This gap has now been filled by a. Husmann and t. F. Rosenbaum of the james franck institute and department of physics at the university of chicago, j. B. Betts, g. S. Boebinger, a. Migliori of the national high magnetic field laboratory at los alamos national laboratory and m.-l. Saboungi of argonne national laboratory in illinois and present their megagauss sensor made of silver chalcogenides in the current ie of nature.

They mixed two parts of silver, one part of selenium and one part of tellurium. Silver selenide (ag2se) and silver telluride (ag2te) are non-magnetic by themselves, but become sensitive to magnetic fields by adding small amounts of excess silver (one part in 10,000) – this discovery was crucial. The physicists integrated the silver chalcogenide into a sensor and, with the help of this new material, succeeded in measuring magnetic fields linearly and uniformly at a distance of. And that up to a coarse order of 600 000 gauss, which is more than a million times the magnetic field of the earth and was the most extraordinary that could be achieved in the laboratory. Conventional magnetic field sensors get at least with the precision from 250’000 manifest problems.

Originally, the research group wanted to explore silver chalcogenides in order to study the structure of glassy materials by the movement of electric charges. As part of this series of experiments, they also applied a magnetic field and were amazed to find the sensory effect.

Your new sensor is small, cheap and sensitive. It is no coarser than the tip of a pencil, or about a cubic millimeter, and the material costs only pennies. The research work was supported by the u.S. Department of energy, and the researchers filed a patent application for the new sensor last year.

The potential applications of the new silver chalcogenide megagauss sensor range from magnetic resonance imaging in medicine (cf. The research ranges from the development of a new sensor (which will be used to study the interior of the sensor with magnetic resonance) to experimental setups that will provide a more detailed understanding of the mechanisms of high-temperature superconductivity, which are still not well understood (cf. The highest jump temperatures).

In which news-and-views-article in the same ie of nature yeong-ah soh and gabriel aeppli of the nec research institute in princeton express confidence that the new sensor will be a breakthrough. It is not yet clear what the magneto-sensory properties of the material are based on. The two authors state:

Husman and colleagues describe a new type of magnetoresistance sensor. Based on a completely different material (than the conventional sensors), this device operates over a coarse range of magnetic field strength and temperature…

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