Thermal expansion and polyamorphism of N2 - C60 solutions

TL;DR

This study investigates the thermal expansion behavior of N2-C60 solutions at very low temperatures, revealing hysteresis indicative of co-existing orientational glasses and providing insights into phase transformations and molecular reorientation.

Contribution

It presents the first detailed analysis of thermal expansion and polyamorphism in N2-C60 solutions across different nitrogen concentrations at cryogenic temperatures.

Findings

Hysteresis in thermal expansion indicates co-existing orientational glasses.

Phase transformation times were estimated.

Differences in glass features depend on nitrogen filling levels.

Abstract

The linear thermal expansion coefficients a(T) of N2 - C60 solutions with 9.9% and 100% of the C60 lattice interstitials filled with N2 have been investigated in the interval 2.2 - 24 K. The dependence a(T) has a hysteresis suggesting co-existence of two types of orientational glasses in these solutions. The features of the glasses are compared. The characteristic times of phase transformations in the solutions and reorientation of C60 molecules have been estimated.