Designing radiation tolerant materials is one of the primary challenges associated with advanced nuclear energy systems. As one type of potential materials, pyrochlore materials, encompassing a wide range of chemistry which is coupled to a remarkable variation of properties, are important in numerous technological applications such as catalysis, piezoelectricity, ferro- and ferrimagnetism, luminescence, giant magnetoresistance, and resistance to radiation damage. Some experiments with nanocrystalline scintillating rare earth oxides and rare earth fluorides on the literature have shown that in some cases nanoscopic dimensions provide essential improvement of the most important scintillation parameters: light yield, kinetics of scintillations, radiation hardness, etc. Hence, in this study, based on a combined co-precipitation and molten-salt synthesis method: nanoparticles of yttrium, lanthanum, praseodymium, gadolinium, erbium and lutetium hafnates were synthesized at 650°C. Of the compositions irradiated with different doses of γ-rays, yttrium, praseodymium, gadolinium and erbium hafnates proved to be the most chemically stable samples, maintaing their initial crystal structure throughout the irradiation process even to the highest expsoure, i.e. 12800 Gy. While further investigation is still undergoing, e.g. on the particle size effects, these rare-earth hafnate nanocrystals have demonstrated with desirable performance due to their robust chemical stability and nanoscopic dimension in radioactive environments, their high thermal stability, and their natural structural compatibility with radionuclide species.