^1,2Anna E. Engle, ³Helen E. Maynard-Casely, ^2,1Jennifer Hanley, ³Christopher Baldwin
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2026.117069]
¹Northern Arizona University, Flagstaff, 86011, AZ, USA
²Lowell Observatory, Flagstaff, 86001, AZ, USA
³Australian Centre for Neutron Scattering, ANSTO, Kirrawee DC, 2232, NSW, Australia
Copyright Elsevier

Ethane (CH), propane (CH), and butane (CH₁₀) are present on many outer solar system bodies but our understanding of their solid phase behaviors is still limited. Linear alkanes are known to exhibit multiple solid phases, with at least one of them being a disordered crystalline phase, wherein the molecules remain in a structured placement but have a freedom of rotation about one or multiple axes. Elucidating the properties of these solid phases is critical for understanding the geochemical and geomorphological processes occurring on icy bodies, thus we undertook an investigation of these three simple alkanes at temperatures relevant to the outer solar system via neutron diffraction. We report on extracted thermal expansion properties, observed phase behaviors, and subsequent analysis of their ’loosely packed’ crystal structures through calculations of crystal voids, contact parameters, and fingerprint plots.