https://phys.org/news/2018-05-russian-physicists-materials-recycling-radioactive.html

As a rule, research papers provide data obtained during studies of the structure and properties of crystallized Ln2M2O7 compounds, obtained using a high-temperature solid-phase synthesis method. In this case, scientists are interested in the amorphous compound's transition to a crystalline state.

According to the research paper's authors, this method makes it impossible to collect data about the formation of nano-crystal structures and their evolution.