Heat Capacity Anomaly of Molecular Hydrogen Adsorbed in Interlayer Space of N+(CH3)4-Montmorillonite

Abstract
Heat capacities of molecular hydrogen H 2 adsorbed in interlayer space of N + (CH 3 ) 4 -montmorillonite have been measured at temperatures between 2 K and 20 K. An anomalous λ-type peak is observed at 7.6 K in the virgin run of the measurement for H 2 concentration less than 5×10 -4 mol/gr.