Calorimetric investigations of phase transitions in the cryolites (NH4)3Ga1−x ScxF6(x=1.0,0.1,0)

The specific heat of the cryolites (NH 4 ) 3 Ga 1− x Sc x F 6 with x =1.0, 0.1, and 0 was measured. The thermodynamic parameters of the phase transitions were determined. A previously unknown phase transition was found in the scandium compound at T =243 K.