Heat capacities of LaDsub(x) (2.5 <= x <= 3) from 1 to 300 K

The heat capacities of LaDsub(x) (2.5 <= x <= 3) were measured in the temperature range from 1 to 300 K. Four sharp heat capacity peaks were found in LaDsub(3.0) at 211, 230.5, 233.5 and 274 K indicating the existence of five polymorphic forms. Only one sharp heat capacity peak was observed at 251 K for LaDsub(2.91) and LaDsub(2.76), while no peaks were observed in the heat capacity of LaDsub(2.53). The electronic specific heat constant ν was found to be zero for LaDsub(x) (2.76 <= x <= 3), indicating that at low temperatures these alloys are semiconductors or semimetals with a small number of conduction electrons. The non-zero ν value for LaDsub(2.53) indicates the existence of a few conduction electrons. The thermodynamic functions Ssub(298.15)0 and (Hsub(298.15)0-H00)/T were determined. (Auth.)