Thermophysical properties of liquid and supercooled ruthenium measured by noncontact methods

Several thermophysical properties of liquid and supercooled ruthenium were measured using electrostatic levitation. Over the 2225–2775 K temperature interval, the density can be expressed as ρ(T) = 10.75 × 10³ – 0.56(T – T_m)(kg ⋅ m⁻³) with T_m = 2607 K. In addition, the surface tension can be expressed as σ(T) = 2.26 × 10³ – 0.24(T – T_m)(mN ⋅ m⁻¹) and the viscosity as η(T) = 0.60 exp[4.98 × 10⁴/(RT)] (mPa ⋅ s) over the 2450–2725 K range. The isobaric heat capacity was estimated as C_P(T) = 35.9 + 1.1 × 10⁻³(T – T_m)[(J/(mol K)] over the 2200–2750 K span by assuming a constant emissivity. The volume expansion coefficient, the enthalpy, and the entropy of fusion were also calculated as 5.2 × 10⁻⁵ K⁻¹, 29.2 kJ ⋅ mol⁻¹, and 11.2 J/(mol K).