THERMAL TRANSPORT-PROPERTIES OF D-ER2SI2O7 AT ROOM-TEMPERATURE

The compound Er2Si2O7 exists in three modifications-a triclinic low-te mperature phase (type B), a monoclinic modification (type C) and a hig h-temperature monoclinic modification (type D). The thermal transport properties of single crystals of D-Er2Si2O7 have been measured by the transient hot strip method. The average thermal conductivity was found to be about 1 W m(-1) K-1. By using the calorimetric method the heat capacity per unit mass of D-Er2Si2O7 at room temperature was found to be 0.52 +/- 0.04 J g(-1) K-1, corresponding to the molecular heat capa city of 31.4R. The calculated molecular heat capacity at room temperat ure is 33R.