High-pressure synthesis of MnO–ZnO solid solutions with rock salt structure: in situ X-ray diffraction studies

Abstract

X-ray diffraction with synchrotron radiation has been used for the first time to study chemical interaction in the MnO–ZnO system at 4.8 GPa and temperatures up to 1600 K. Above 750 K, the chemical reaction between MnO and ZnO has been observed that resulted in the formation of rock salt (rs) Mn_1−x Zn _x O solid solutions (0.3≤x≤0.7). The lattice parameters of these solid solutions have been in situ measured at high pressures as a function of temperature and corresponding thermal expansion coefficients have been calculated.

Keywords:

• zinc oxide
• manganese (II) oxide
• solid solutions
• high pressure
• high temperature

Acknowledgements

Experiments have been performed during beamtime allocated to the Project I-20090172 EC at HASYLAB-DESY and have received funding from the European Community's Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 226716. This work was also supported by Russian Foundation for Basic Research (Project No. 09-03-90442-Y ) and Ukrainian Foundation for Basic Research (Project No. Φ28.7/008). P.S.S. is grateful to the French Ministry of Foreign Affairs for financial support (BGF fellowship No. 2007 1572).

Notes

, where γ is the concentration of turbostatic stacking faults 14.

For rs-Mn_0.7Zn_0.3O, an abrupt (by more than one order of magnitude) increase in the intensity of the 220 reflection is observed, while 331 and 400 reflections disappear almost completely; for Mn_0.3Zn_0.7O, 311 and 420 reflection intensities increase twice, and the intensity of 220 and 511 reflections decreases. No changes in reflection intensities are observed for pristine manganese (II) oxide at the same p, T conditions.