Phase transitions and undercooling in confined gallium

Disordered matter under extreme conditions: X-ray diffraction, electron spectroscopy and electroresistance measurements

“…The last two sections are devoted to the presentation of novel equipments for electrical resistance measurements both under high-temperature/ pressure (Section 6) and low-temperature conditions (Section 7). Interesting applications of these techniques, discussed in those last Sections, include studies of phase transitions occurring in metastable liquid and solid phases in Ga films at low-temperature (see [12,18] for similar studies on bulk samples) and in solid Bi at high-pressure and temperature (see for example Ref. [20,21,19] and our recent work [22]).…”

Supercooling of nanoscale Ga drops with controlled impurity levels

“…The possibility of significant supercooling in small droplets has been investigated extensively following the pioneering work of Turnbull [1]. It has been shown that small particles can melt and freeze at temperatures different from the bulk [2][3][4], undergo significantly higher supercooling [4], crystallize along different pathways [5], and in structures different from the bulk [6][7][8][9][10][11]. The extent of achievable supercooling can presumably vary with droplet size, purity [12], interactions with supports, etc.…”

Preparation and Internal Friction of Nanoscale Gallium Droplets

“…In the figure, curve 1 was obtained during the first heating run from 260 to 340 K for the specimen cooled to 220 K. One can see that there is an endothermic peak associated with the melting of Ga droplets at 303 K. Then the specimen was cooled from 340 to 280 K. But during the second heating run from 280 to 340 K, the endothermic peak disappeared (curve 2). It indicates that the n-Ga droplets remain in liquid state even if the specimen was cooled down to 280 K. The cooling curve of DSC (curve 3) shows an exothermic peak at 269 K, indicating that the solidification of n-Ga droplets can only occur when the specimen was cooled down to below 269 K. The undercooling of confined Ga droplets in PS is found to be about 34 K. Larger undercooling phenomena of confined nanoscale Ga droplets have been observed by Cicco et al [8,9].…”

“…The structure and undercooling of liquid gallium droplets were studied by a number of authors, such as [6][7][8][9]. It was found that the confined Ga droplets exhibited significant undercooling, and that there appeared several crystalline phases different from bulk Ga.…”