Noun
liquid helium (uncountable)
(physics) The liquified form of helium that does not solidify even at absolute zero; it shows unusual properties, such as superfluidity, due to quantum effects.
By reducing the pressure of the liquid helium he achieved a temperature near 1.5 K. These were the coldest temperatures achieved on earth at the time. Source: Internet
All three materials showed Curie–Weiss paramagnetic behavior from liquid helium to room temperature. Source: Internet
He proposed a theoretical explanation of the superfluid properties of liquid helium in 1949; two years later the physicist Richard Feynman independently proposed the same theory. Source: Internet
Solid helium requires a temperature of 1–1.5 K (about −272 °C or −457 °F) and about 25 bar (2.5 MPa) of pressure. citation It is often hard to distinguish solid from liquid helium since the refractive index of the two phases are nearly the same. Source: Internet
In traditional superconducting solenoids, liquid helium is used to cool the inner coils because it has a boiling point of around 4 K at ambient pressure. Source: Internet
It had to be cooled by liquid helium and thus did not find practical applications. Source: Internet