Enhanced radiation tolerance in nanocrystalline MgGa2O4

The authors demonstrate a substantial enhancement in radiation-induced amorphization resistance for single-phased nanocrystalline (NC) versus large-grained polycrystalline MgGa2O4. NC and large-grained MgGa2O4 were irradiated at ∼100K with 300keV Kr++ ions to fluences ranging between 5×1019 and 4×1020Kr∕m2. Large-grained MgGa2O4 samples began to amorphize by a fluence of 5×1019Kr∕m2, while NC MgGa2O4 remained crystalline with no evidence for structural changes (other than moderate grain growth in the lowermost implanted region), to a fluence of 4×1020Kr∕m2. To our knowledge, this is the first experimental study to reveal enhanced amorphization resistance in an irradiated, single-phase, NC material.