Single crystals of undoped LiWO and LiWMoO: formation enthalpies, heat capacity in the temperature range 320-997 K.

The LiWO single crystal was first grown by applying the Czochralski technique with weight control and low-temperature-gradients. A single crystal of LiWO is one of the perspective materials for researching rare events. The heat capacity for a LiWMoO single crystal has been determined by DSC calorimetry in the temperature range 320-997 K for the first time. No anomalies in the heat capacity associated with phase transitions were found. The standard formation enthalpy for the LiWO single crystal was studied using reaction calorimetry. It has been shown that the relation of standard formation enthalpies for LiWMoO ( = 0.15-0) with function (1-)W + Mo are close to linear, which allows one to predict the thermodynamic properties for single crystals with isotopes LiWMoO and LiWO. It was shown that single crystals with isotopes are more thermodynamically stable than without isotopes.