Using Variable Temperature Powder X-ray Diffraction To Determine the Thermal Expansion Coefficient of Solid MgO

A laboratory experiment using variable temperature powder X-ray diffraction to determine the thermal expansion coefficient of solid magnesium oxide (Mgo) is presented. Students determine the cell constant for Mgo as a function of temperature and use these data to calculate the molar volume, the thermal expansion coefficient, and the density of Mgo as a function of temperature. The value obtained by students for the linear expansion coefficient of Mgo agrees with the literature values. Data are provided so that students without access to a variable temperature powder diffractometer can analyze the data as an exercise.