Thermodynamic characteristics of sodium ditungstate single crystal

The single crystal of Na₂W₂O₇ has been grown by the low-temperature-gradient Czochralski technique. The thermo- dynamic properties (standard enthalpy of formation, lattice enthalpy and stabilization energy), the knowledge of which is necessary to improve the growth technology, have been measured using reaction calorimetry. It has been shown that in the Na₂W₂O₇– Na₂Mo₂O₇ series, the luminescence wavelength increases from 540 to 650 nm, respectively, along with a change in the lattice enthalpy from −49030 to −54730 kJ mol⁻¹.