Multifunctional RFe3(BO3)4 Materials: Quality ControlK. N. Boldyrev, M. N. Popova, A. D. Molchanova, T.N. Stanislavchuk, L. N. Bezmaternykh and I.A. GudimEPJ Web of Conferences, 103 (2015) 09001DOI: https://doi.org/10.1051/epjconf/201510309001