INVESTIGATION OF THE STRUCTURE OF STRONTIUM CHLORIDE AT HIGH-TEMPERATURES USING NEUTRON-DIFFRACTION

Strontium chloride shows a broad anomaly in its specific heat at a temperature Tc approximately 730 degrees C well below its melting temperature of 873 degrees C, which arises from the development of disorder in the anion sublattice. Neutron diffraction experiments are performed to investigate the nature of the time-averaged disorder at temperatures up to 820 degrees C. From the data it is concluded that at 820 degrees C about 3 per cent of the Cl- ions leave regular lattice sites and occupy interstitial positions.