Near-Infrared Absorption Spectrum of Solid Methane at the λ Point

Abstract

Observations on the near‐infrared absorption spectrum of solid methane in the region of ν₁+ν₄ and ν₃+ν₄ over a temperature range of 6° to 33°K are presented and discussed. There is no evidence of molecular rotation, and the observations are shown to lead to an interpretation involving an order‐disorder transition. Approximate f numbers for the transitions are measured.