High-temperature abnormal behavior of resistivities for Bi–In melts

Are there phase transitions in liquid metallic alloys?

“…they (and we) did not consider as correct the first heating measurements. Having developed since many years an experimental design (cell(s) + measurement methods) able to make accurate resistivity measurements, we feel necessary to check if we observe the same behaviour as that reported by Xi et al [1] and Yu et al [2] and others [3 to 7] by using our experimental cell and the same experimental process than the Hefei's group.…”

“…We reproduce on figure 2 four measurements that we obtained successively and compared with the electrical resistivity of Xi et al [1]. Arrows indicate that we either apply vacuum to empty the capillary or increase the pressure to decrease the size of bubbles (if present in the capillary).…”

“…To compare our results with Xi et al [1] and Yu et al [2], we try to reproduce their experiments by using the same experimental method and process. Our alloys were prepared at the expected composition from pure elements (purity: 99.999% for In, Bi and Pb), melted under vacuum in a quartz tube, heated, shacked, then cooled rapidly at room temperature under argon pressure in order to get an alloy "as concentration homogenous" as possible.…”

“…Xi et al [1] measured six different compositions of liquid Bi-In alloys between the melting point and 1000°C. They observed a drastic change of the temperature coefficient of the resistivity of four alloys, the most important was observed for Bi 52.73 In 47.27 at% 2 .…”

“…The question arises if such behaviour may be explained by purely experimental problems or if we must invoke a new physical phenomenon. The object of this work is to arbitrate between a "phase transition" in the liquid state as claimed by ref [1] to [7] and experimental phenomena like liquid concentration homogeneity or/and release of bubbles…. Among the different possible experimental problems, the most encountered is the release of gases which can be dissolved or/and adsorbed or/and resulting from an oxide or hydroxide decomposition or/and of bubbles due to the vapour pressure of the metals itself when approaching their boiling point.…”