The effects of hydrogen absorption in U3Si5 and its thermodynamic properties

Abstract

The hydrogen absorption behavior of ▪ was examined using a Sieverts apparatus. Experimental results revealed the formation of a hydride phase with a stoichiometry reaching ▪ at pressures up to 250 kPa and temperatures below 300°C. By employing Van 't Hoff analysis, the enthalpy and entropy of formation for the newly formed hydride phase were measured as -19.73 kJ⋅mol−1 and -251.18 J⋅mol−1⋅T−1, respectively. Rietveld refinement showcased an expansion in lattice parameters a and c, resulting in an overall increase in unit cell volume of up to 8%; volume expansion can induce structural failures within the material.