The origin of the double peak at 260 K in calorimetric measurements on solid C60

✍ Scribed by Anup K. Gangopadhyay; Tomek Kowalewski; James S. Schilling

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 486 KB
• Volume: 239
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00451-9

✦ Synopsis

The fcc-sc phase transition in solid C6o in calorimetric measurements is usually manifested as a single sharp peak centered at a temperature near T = 260 K. In the present study it is shown that small amounts ( < 1 wt%) of impurities such as C7o can give rise to additional features, including a second peak at 10-20 K below the transition temperature. In contrast, the presence or absence of such double-peak anomaly in high-purity (> 99.5%) samples is determined by the kinetics of crystallization. We conclude that impurities as well as crystal imperfections are the primary source of the double-peak anomaly.