Physicist Heike Kamerlingh Onnes and Superconductivity

1289 Words3 Pages

In 1911, Dutch physicist Heike Kamerlingh Onnes discovered that the resistance of mercury absolutely disappears at temperatures below about 4K. This phenomenon is called superconductivity; correspondingly, materials which have this property would be called superconductors. Because of this great discovery, in 1913, he won a Nobel Prize in physics for his research in this area.
[2]
The technological development of superconductivity was hampered by the cost of producing the extremely low temperatures required to achieve the effect. Until 1986, new superconducting ceramic materials were discovered which have considerably higher critical transition temperatures. Gradually, as more and more metals, alloys, and compounds are found to have superconductivity and be cheap to produce, the practical application of superconducting devices at room temperature may eventually become commonplace. Excellent properties and attractive prospects of superconductors have been found since the day they were discovered.
Superconductors have been used in many fields in recent times, and this paper will mainly discuss the classifications, properties, applications, etc., to help people understand
Da Wang, Jack
1
superconductors better .
2. Classification
2.1 Sorted by Material:
Superconductors can be made from some pure elements, such as mercury and lanthanum, and some allotropes of carbon, such as graphite.
[4]
Some alloys such as
Niobium-titanium
[5] also have superconducting properties. Ceramics can be used as superconductors as well, such as yttrium barium copper oxide (YBCO) family.
2.2 Sorted by The Meissner Effect
:
Type-I Superconductors:
[8]
Type-I superconductors all show the similar magnetization curve in a magnetic field, as shown in figure 1: ...

... middle of paper ...

...e amount of Ic that passes through each unit cross-sectional area of the superconductor is called the critical current density, which is represented by Jc.
All of these critical values severely restrict the conditions for using superconductors, and thus finding new superconductors with higher tolerances has become an important research topic for scientists. For example, from 1911, when Dutch physicist Kamerlingh Onnes discovered superconductivity of mercury (Tc = 4.2K), to 1986, the highest Tc found was 23.2K
(Nb3Ge, 1973). In 1986, Swiss physicists Bednorz and Müller discovered superconductivity in a lanthanum-based cuprate perovskite material, which had a Tc of 35 K.
[15]
And only after one year, the new record of Tc has reached about 100K. This breakthrough has opened up a bright future for the application of superconductors. This led to Bednorz and Müller winn

More about Physicist Heike Kamerlingh Onnes and Superconductivity

Open Document