Molar volume of pure liquid 4He: dependence on temperature (50–1000 mK) and pressure (0–1.57 MPa) Original Research Article

The molar volume of pure liquid 4He, V40(T,P) has been determined by a capacitance-measurement technique in the temperature range from 50 to 1000 mK and the pressure range from 0 to 1.57 MPa. For any practical purposes, the obtained data are fitted with an appropriate formula based on the Landauʹs phonon–roton model. Our empirical formula can reproduce V40(T,P) within the accuracy of ±5×10−10 m3/mol.