Specific heats of ternary oxides in the Li–U(VI)–O System

Seven ternary oxides; Li₄UO₅, Li₂UO₄, Li₂₂U₁₈O₆₅, Li₂U_1.75O_6.25, Li₂U₂O₇, Li₂U₃O₁₀ and Li₂U₆O₁₉ in the system Li–U(VI)–O were prepared by solid-state reaction route and characterized by X-ray diffraction method. Specific heats of these compounds were measured by differential scanning calorimetry in the temperature range from 300 to 860 K. The specific heats show a decreasing trend with increase in UO₃(s) content in these lithium uranates. However, the specific heat per gram atom shows an increasing trend with decrease in number of oxygen atoms in the formula unit.