Coefficient of Expansion of Liquid Helium II

The coefficient of thermal expansion of liquid helium ii was measured from the λ point down to 0.85^∘{}K. Near the λ point the coefficient varies very rapidly with temperature and may tend to minus infinity at the λ point. The coefficient becomes positive below 1.15^∘{}K. The results are discussed in relation to Landau's theory and a value for (ρΔ)(∂Δ∂ρ) deduced.