Crystalchemistry and Thermodynamics in ZnMgO₂, Zn₂MgO₃ and Zn₃MgO₄ compositions.

In 2016 was reported the ZnMgO₂ 115 K, Zn₂MgO₃ 132 K y Zn₃MgO₄ 152 K superconductors. Our interest was study the thermodynamic behaviour, which did not reported jet. Of course, also study their crystal structure and magnetic properties. Searching in the phase diagrams thermodynamic equilibrium, we found the binary Zn0-MgO system. Then the SC compositions were in the region of the mixture of zincite-periclase solid solutions.

By simultaneous SDT (DCS-TGA) analysis it is observe the reactions and oxygen changes temperature. The solid solution mechanism was complex, occurs a cationic substitution and instantaneous accepted our lost of anions.

XRD was used to determine the reagents purity, crystal structure and reactions results. Gives the information of the formation of the mixtures of the solid solutions. CIF data helps to determined (hkl) displacement in the würtzite crystal structure, that shows what planes happened the cation substitution. For example, (110) indicates Zn⁺² ions substitution by Mg⁺² cation. RAMAN gives only ZnO vibration, because are in a high proportion in the studied compositions. SQUID corroborate that the compositions worked were not superconductors.