New Nuclear Radiation Detector Made by Core-Shell Magnetic Nanoparticles

Iron/iron-oxide core-shell nanoparticles (NPs) have been found potential nanomaterials for radiation sensing and monitoring in the nuclear radiation. It has been shown extremely sensitive behavior under Si²⁺ ions irradiation even at very low dose of ion fluxes. Since heavy ions behave like neutron in terms of the radiation effect and defect creation, the core-shell NPs have been proposed for highly sensitive neutron radiation detection at high temperature in the core of the nuclear reactor. In order to study the high temperature structural and morphological behavior of the core-shell NPs, annealing tests have been performed up to 800 ⁰C in vacuum, oxygen and argon environment. The ~18 nm size of the as prepared NPs increases slowly on annealing up to 500 ⁰C in all three environments but increases abruptly in argon and oxygen environment but slow in vacuum when heated to 800 ⁰C. The x-ray diffraction studies have shown that the iron core remains in the core-shell NPs only when they are annealed in the vacuum environment, which is important for the high temperature neutron detection in the core of nuclear reactor. The size distribution, size growth mechanism and phase transformation of the NPs will be discussed in this presentation.