High pressure synthesis of FeO-ZnO solid solutions with rock salt   structure: in situ X-ray diffraction studies
  X-ray diffraction with synchrotron radiation has been used for the first time to study chemical interaction in the FeO-ZnO system at 4.8 GPa and temperatures up to 1300 K. Above 750 K, the chemical reaction between FeO and ZnO has been observed that resulted in the formation of rock salt (rs) Fe1-xZnxO solid solutions (0.3 \leq x \leq 0.85). The lattice parameters of these solid solutions have been in situ measured as a function of temperature under pressure, and corresponding thermal expansion coefficients have been calculated. 
P.S. Sokolov, A.N. Baranov, C. Lathe, V.L. Solozhenko
cond-mat.mtrl-sci