Single crystals of undoped Li 2 WO 4 and Li 2 W 1−0.0125 Mo 0.0125 O 4 : formation enthalpies, heat capacity in the temperature range 320–997 K

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 50; no. 35; pp. 12130 - 12136
• Main Authors: Matskevich, Nata I., Shlegel, Vladimir N., Semerikova, Anna N., Samoshkin, Dmitrii A., Grigorieva, Veronika D., Stankus, Sergei V., Kuznetsov, Vitalii A., Ponomareva, Sofiya A., Zaitsev, Valerii P., Novikov, Andrei Yu
• Format: Journal Article
• Language: English
• Published: 14.09.2021
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/D1DT01620B

The Li 2 WO 4 single crystal was first grown by applying the Czochralski technique with weight control and low-temperature-gradients. A single crystal of Li 2 WO 4 is one of the perspective materials for researching rare events. The heat capacity for a Li 2 W 1−0.0125 Mo 0.0125 O 4 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 Li 2 WO 4 single crystal was studied using reaction calorimetry. It has been shown that the relation of standard formation enthalpies for Li 2 W 1− x Mo x O 4 ( x = 0.15–0) with function (1− x )W + x Mo are close to linear, which allows one to predict the thermodynamic properties for single crystals with isotopes Li 2 W 186 1−0.0125 Mo 100 0.0125 O 4 and Li 2 W 186 O 4 . It was shown that single crystals with isotopes are more thermodynamically stable than without isotopes.