Kamerlingh-Onnes

Real gases follow the ideal-gas equation (A2.1.17) only in the limit of zero pressure, so it is important to be able to handle the tliemiodynamics of real gases at non-zero pressures. There are many semi-empirical equations with parameters that purport to represent the physical interactions between gas molecules, the simplest of which is the van der Waals equation (A2.1.50). However, a completely general fonn for expressing gas non-ideality is the series expansion first suggested by Kamerlingh Onnes (1901) and known as the virial equation of state ... 

H. Kamerlingh Onnes (Leiden) properties of matter at low temperatures and production of liquid helium. 

Kamerlingh Onnes does not fit the description of a loner on the contrary, he created one of the first laboratories to be set up as if it were a factory. Per Dahl in his comparison between Kamerlingh Onnes and his British counterpart, James Dewar, states that Onnes, to be sure was paternalistic, opinionated, and a man of strong principles—traits not uncommon among the moguls of late nineteenth-centuiy science—but that he proved to be a benevolent leader, kind and scrupulously fair in his relations with friends and pupils alike—behavior that was certainly within the norms ofhis time. 

After Kamerlingh Onnes was appointed professor in experimental physics at the University of Leiden in 1882, he stated in his inaugural lecture that physics is capable of improving the well-being of society and proclaimed that this should be accomplished primari-... 

All currents that had to be measured were sent to a central measurement room in which many mirror galvanometers were situated on top of vibration-free columns that were separated from the foundations of the building. One should realize that the many announcements in the early literature of the liquefaction of specific gases pertained to not much more than a mist or a few drops Kamerlingh Onnes planned to make liquid gases by the gallon. A separate hydrogen liquefaction plant was located in a special room with a roof that could be blown off easily. 

The result was called by Dutch physicist II. A. Lorentz perhaps the most beautiful pearl of all [of Kamerlingh Onnes s discoveries]. However, as H. B. G. Casiniir describes in his memoirs, he refused to give any credit to the graduate student who obsewed the phenomenon and who realized its importance. 

Heike Kamerlingh Onnes was awarded the Nobel Prize in physics in 1913. 

Bmyn Oubotcr, R. dc. (1997). TTcikc Kamerlingh Onnes s Discovery of Superconductivity. Scientific American 275 98-103. 

Handel, J. van den. (1973). Kamerlingh Onnes, Heike. In Dictionary of Scientific Biography, Vol. 7, ed. C.C. Gillispie. New York Charles Scribner s Sons. 

Meijer, P. H. E. (1994). Kamerlingh Onnes and the Discovery of Superconductivity. American Joanial of Physics la-.nos-im. 

For very low temperatures a lead wire is used as thermometer, with a heating coil of constantan wire (Kamerlingh Onnes). 

The boiling-point of liquid helium is 4 20° abs. (Kamerlingh Onnes, Commun. Phys. Lab. Leiden, No. 119, 1911). A temperature lower than 1 5° abs. has recently been obtained by the rapid evaporation of solid helium. 

Low-temperature research requires hard work and imagination, but successful advances are richly rewarded. Seven Nobel Prizes in physics and chemistry have been awarded for low-temperature research. The first, in 1913, went to the Dutch physicist Heike Kamerlingh Onnes, who discovered how to cool He gas to 4.2 K and convert it into a liquid. The American William Giauque received the 1949 prize in chemistry and the Russian Pyotr Kapitsa won the 1978 prize in physics. Each was honored for a variety of discoveries resulting from low-temperature research, and each developed a new technique for achieving low temperature. 

The discovery of superconduction was made at Leiden University, by Heike Kamerlingh Onnes back in 1911 whilst experimenting with the electrical resistance of mercury, cooled to liquid helium temperature. His efforts were recognised with the Nobel Prise for Physics in 1913 and much later, a... 

In 1908, Kamerling-Onnes got the liquefaction of helium (discovered by Janssen e Lockyer during the solar eclipse of 18 August 1868). Kamerlingh-Onnes obtained in Leiden 60 cc of liquid helium extracted from several tons of monazite sable imported from India. Kamerlingh-Onnes himself discovered the X-transition and the superfluidity in 4He and in 1911 the superconductivity of Hg, a particularly pure substance at that time. In the race towards lower and lower temperatures, Kamerling-Onnes, pumping on liquid 4He, obtained 0.7K in 1926. 

The phenomenon of superconductivity was discovered at the beginning of the twentieth century by the Dutch physicist H. Kamerlingh Onnes, during the first attempts to liquefy helium (which at atmospheric pressure boils at 4.2 K). After refining the technique of helium liquefaction, in 1911, Onnes attempted to measure the electrical resistance of metals at these extraordinary low temperatures, and realized that at 4 K the resistance of mercury, as well as that of other metals indicated in Figure 1, became too low to be measured. This change in electrical property became the indication of the new superconductive physical state. The temperature below which materials become superconducting is defined as the critical temperature, Tc. 

For example, in 1911, Dutch physicist Heike Kamerlingh Onnes cooled some mercury to the hoiling point of liquid helium 4 K. He found that at this low temperature, the mercury developed an astonishing property. The super-cooled mercury had zero resistance when an electric current passed through it. In other words, none of the energy of the electrical current was given off as wasted heat. The mercury had become a superconductor—a material with no resistance to electric current. 

Figure 1 The resistive ratio of solid mercury versus absolute temperature(uncorrected scale) as actually reported by H. Kamerlingh Onnes (1). This observation marked the discovery of superconductivity.

Superconductivity has not only been beneficial to science and technology but also has been highly rewarding to its scientists. Thus far, Nobel Prizes in Physics have been awarded on four occasions to scientists working in this area. The first of these was for the discovery of superconductivity by Kamerlingh Onnes, awarded in 1913. In 1972 the prize went to John Bardeen, Leon Cooper, and Robert Schrieffer for the BCS theory. The following year (1973), the Prize was awarded to Brian Josephson, L. Esaki and I. Giaever for the... 

H. Kamerlingh Onnes. Akad. van Wetenschappen, Proceedings from the Section of Sciences.(Amsterdam), 14 113-115, and 818-821 (1911). 

The discovery of superconductivity was not very dramatic. When Dutch physicist Heike Kamerlingh Onnes succeeded in liquefying helium in 1908 he looked around for something worth measuring at that temperature range. His choice feU upon the resistivity of metals. He tried platinum first and found that its resistivity continued to decline at lower temperatures, tending to some small but finite value as the temperature approached absolute zero. He could have tried a large number of other metals with similar prosaic results. But he was in luck. His second metal, mercury, showed quite unorthodox behavior, and in 1911 he showed that its resistivity suddenly... 

In 1908, Kamerlingh Onnes succeeded in liquefying helium, and this paved the way for many new experiments to be performed on the behaviour of materials at low temperatures. For a long time, it had been known from conductivity experiments that the electrical resistance of a metal decreased with temperature. In 1911, Onnes was measuring the variation of the electrical resistance of mercury with temperature when he was amazed to find that at 4.2 K, the resistance suddenly dropped to zero. He called this effect superconductivity and the temperature at which it occurs is known as the (superconducting) critical temperature, Tc. This effect is illustrated for tin in Figure 10.1. One effect of the zero resistance is that no power loss occurs in an electrical circuit made from a superconductor. Once an electrical current is established, it demonstrates no discernible decay for as long as experimenters have been able to watch ... 

C. J. Ballhausen, Kobenhaven Universitets Fysisk-Kemiske Institut, Kemisk Laboratorium IV, Copenhagen, Denmark J. J. M. Beenakker, Rijksuniversiteit te Leiden, Kamerlingh Onnes Laboratory, Leiden, Netherlands... 

In 1901, H. Kamerlingh Onnes introduced a fundamentally new and improved description of real gas PVT properties in terms of the virial equation of state. [The word virial, deriving from the Latin word viris ( force ) was introduced into physics by R. Clausius, whom we shall meet later.] This equation expresses the compressibility factor Z(Vm, T) in terms of a general power series expansion in inverse molar volume Vm. The starting point for the virial expansion is the ideal limiting behavior (2.12), which can also be expressed as... 

---