화학공학소재연구정보센터
Journal of Chemical and Engineering Data, Vol.65, No.4, 1523-1530, 2020
Thermodynamic Study of Lithium Tungstate Single Crystals Doped by Molybdenum (Li2W1-xMoxO4, x=0.1 and 0.15)
The single crystals Li2W0.85Mo0.15O4 and Li2W0.9Mo0.1O4 have been grown by a low-temperature-gradient Czochralski technique as representatives of promising materials for scintillating cryogenic bolometers. Thermodynamic properties and their relationship with structural parameters to improve and extend the device portfolio with special emphasis on formation enthalpies, thermodynamic stability, and lattice enthalpies have been revealed. Solution enthalpies of Li2CO3, MoO3, and Li2W0.85Mo0.15O4 and Li2W0.9Mo0.1O4 single crystals have been measured in 0.40162 mol kg(-1) aqueous KOH. The standard formation enthalpies (Delta H-f(0) (Li2W0.85Mo0.15O4, s, 298.15 K) = -1590.8 +/- 2.0 kJ mol(-1); Delta H-f(0) (Li2W0.9Mo0.1O4, s, 298.15 K) = -1594.1 +/- 2.3 kJ mol(-1)), formation enthalpies from simple oxides, and lattice enthalpies have been determined. As a result, the dependences of formation enthalpies and lattice enthalpies for Li2W1-xMoxO4 on tolerance factors have been found to be linear. It has been discovered that the thermodynamic stability and lattice enthalpies of Li2W1-xMoxO4 are increased when the tolerance factor tends to one. It has been established that single crystals Li2W0.85Mo0.15O4 and Li2W0.9Mo0.9O4 are several times more thermodynamically stable than ZnMoO4 and CdWO4.