Improved mechanically induced synthesis of nanocrystalline gadolinium oxymolybdate

A simple one-step mechanically induced route was used for synthesis of Gd2MoO6 (GMO). Single-phase with disordered structure was obtained after 12 h of milling. Elemental analysis revealed continuous decomposition of ammonium orthomolybdate. SEM-EDS (energy dispersive X-ray spectrometry) analysis confirmed a homogeneous distribution of Gd, Mo, and O with the atomic ratio 22.2:8.6:69.2% corresponding to Gd1.998Mo0.774O6.228. Aside from conventional X-ray diffraction, we here paid an effort to obtain the information about the local structure of our GMO by Gd-155 Mossbauer spectroscopy. The analysis of temperature dependence of magnetic susceptibility and field dependence of magnetization of GMO was confirmed to be similar to those of the mechano/thermally synthesized Gd2MoO6 mentioned in our previous study (Tothova et al., 2019) [1]. Small deviations suggest the presence of nonmagnetic unreacted materials in the starting mixture used in the present mechanosynthesis. We would like to emphasize that the present simplified synthesis without annealing steps leads to GMO with very good quality in the terms of magnetic properties.

Automated summary

A simple one-step mechanically induced route was used to synthesize Gd2MoO6 with a disordered structure. The elemental analysis confirmed a homogeneous distribution of Gd, Mo, and O. Gd-155 Mossbauer spectroscopy provided information about the local structure of GMO. The simplified synthesis method resulted in GMO with excellent magnetic properties.