Exploring the Oxygen Order in Hg-1223 and Hg-1201 by 199Hg MAS NMR
  We demonstrate the use of a high-resolution solid-state fast (45 kHz) magic angle spinning (MAS) NMR for mapping the oxygen distribution in Hg-based cuprate superconductors. We identify observed three peaks in 199Hg spectrum as belonging to the different chemical environments in the HgO? layer with no oxygen neighbors, single oxygen neighbor, and two oxygen neighbors. We discuss observed differences between Hg-1201 and Hg-1223 materials. 
Raivo Stern, Ivo Heinmaa, Dmitriy A. Pavlov, and Ingrid Bryntse