The supercooling behaviors of n-alkanes during the solid-liquid phase transition offer a promising explanation to the phenomenon of energy conversion and transfer across seasons and regions observed on Titan. However, research on the supercooling behaviors of n-alkanes under Titan's internal pressure (P) and temperature (T) conditions (<4.9 GPa; 93-900 K) remains inadequate. Here, we present findings from laboratory experiments conducted under high P-T conditions, exploring the P-T phase diagrams and supercooling behaviors of six n-alkanes [n-CnH2n+2 (6 ≤ n ≤ 11)]. The current results indicate that all measured n-alkanes exhibit supercooling behaviors, with the supercooling degree increasing as pressure increases. At the same pressure, the supercooling degree of both odd and even n-alkanes decreases as the carbon chain length increases. Under Titan's central pressure of 4.9 GPa, n-heptane shows the highest supercooling degree among the measured n-alkanes, reaching up to 63 K.
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