Change in Relative Density of Natural Rock Minerals Due to Electron Irradiation

Abstract

We investigated changes in the density of natural rock minerals following high-energy electron irradiation, using the plasmon peak shift of electron energy-loss spectra and transmission electron microscopy. The target materials were the natural rock minerals α-quartz, orthoclase, anorthite, albite, biotite, muscovite, and chlorite. These crystalline minerals can be classified into three groups based on their Si-network geometries: 3-dimensional 6-member ring; 4-member ring + 6-member ring; and planar 6-member ring. The metamictization rates and changes in relative density are discussed using a phenomenological model, which we used to identify the physical parameters that describe the metamictization process as a function of the volume density of Si and Al atoms, or Si atoms alone, in the crystal structures. The relative densities following metamictization all decreased by more than a few percent, except for albite, which became denser. These results suggest that radiolysis damage causes initial compaction, then metamictization, characterized by the expansion of the Siand Al-polyhedra in the aggregate. The stability of concrete containing α-quartz, orthoclase, and anorthite should be further investigated in the light of the present results.

Development of Soundness Assessment Procedure for Concrete Members Affected by Neutron and Gamma-Ray Irradiation

“…It is unclear why the dimensions of aggregates (except limestone) instead expanded. An expansion strain value of 4% for quartz has been reported in past research following electron irradiationinduced metamictization (Maruyama and Muto 2016), but the data obtained here did not reach this value. Taking into account the large variation and the little differ- Fig.…”

“…A recent study reported that quartz subject to 100-keV electrons expands by only 4%, which is markedly smaller than the 16-18% expansion caused by neutron irradiation. Thus, the mechanism of neutron metamictization is different from that of the electroninduced metamictization (Maruyama and Muto 2016).…”

“…Given this analysis, it was attempted to interpolate a model proposed in the past research that explicitly incorporates thermal healing in a real-world reactor setting (Nakano et al 2005;Maruyama and Muto 2016). This was a three-layer model that includes a crystalline phase, an intermediate phase, and a metamictized phase, and which differs from the nucleation and growth model.…”

Low‐Resistive LiCoO2/Li1.3Al0.3Ti2(PO4)3 Interface Formation by Low‐Temperature Annealing Using Aerosol Deposition

“…When the sample's composition and chemical bonding character is almost constant, a lower energy position in the plasmon energy center can be understood as a lower density area in the sample, that is, less contact state. [ 34 ] Thus, it will be concluded that annealing at 300 °C provides superior contact without generating critical side reactions, leading to enhance the electrochemical active area and then reduce the R int .…”

Modal Analysis of Rock Forming Minerals: Contribution of XRD/Rietveld Analysis Compared to the Classic Point Counting Method

“…The RIVE is related to many properties of the original rock like its mineral composition, grain size and orientation of minerals (Denisov et al 2012;Maruyama et al 2017;Le Pape et al 2020). For instance, it is well known that silicate-bearing aggregates develop higher RIVE compared to carbonate-bearing aggregates (Maruyama and Muto 2016;Le Pape et al 2018). Therefore, to assess the degradation risk of the biological shield, it is neces-sary to have the accurate mineralogy of aggregates and their properties in a such environment (Maruyama et al 2017;Le Pape et al 2020).…”