Tensile Strength of Liquid Helium II

Abstract

THE tensile strength of a liquid is defined as the maximum negative pressure (P) that a liquid in an isothermal metastable state can sustain before returning to a two-phase system. Mathematically, this might be expressed as the value of P at which (∂P/∂V)_T = 0, where V represents the volume of the liquid at temperature T. According to Temperley¹, if Van der Waals's equation of state be assumed to hold for a liquid and the condition that (∂P/∂V)_T = 0 be applied, the tensile strength may be calculated. Benson and Gerjuoy², in working with the reduced form of this equation, arrived at: where ϕ = V/V_c, θ = T/T_c, π = P/P_c and the subscript c stands for critical value, by applying the condition: Values may be assigned to θ and the resulting cubic in ϕ will give rise to a real root which may in turn be substituted in to give reduced values of the tensile strength.