Low-temperature thermal expansion of Mg3N2

Lattice parameter and thermal-expansion coefficient for magnesium nitride, Mg 3 N 2 , were determined using X-ray powder diffraction at the B2 beamline in Hasylab (DESY) in the temperature range from 11 K up to 304.5 K. The relative change of lattice parameter on raising the temperature in the studied range is about 0.14%. At 300 K, its value is 9.9644(1) A and the linear thermal expansion coefficient derived from a polynomial approximation is a =1.1×10 −5 K −1 .