Electrical resistivity of liquid and solid sodium
Abstract
The electrical resistivity of sodium contained in a stainless-steel capillary has been determined between 19 and 300° by means of a Kelvin–Wheatstone Bridge. The resistivity of the liquid between 97·8 and 300° obeys the equation ρL(µΩ cm.)=a+bT+cT2+dT3–eT4 where T is in °C, and the constants have the values: a, 6·87; b, 2·44 × 10–2; c, 2·67 × 10–5; d, 1·07 × 10–7; e, 2·67 × 10–10. The corresponding equation for the solid over the temperature range 19–97·8° is ρS(µΩ cm.)=a+bT+cT2+dT3 where the constants are: a, 4·35; b, 2·13 × 10–2; c, 6·25 × 10–6; d, 1·04 × 10–7. The results are compared with published values, and factors responsible for the variation in resistivity with change of phase are considered briefly. The design of apparatus whereby spurious post-melting phenomena are avoided is discussed.