Abstract
Natural silicate mineral of pumpellyite, Ca2MgAl2(SiO4)(Si2O7)(OH)2·(H2O), point group A2/m, has been studied concerning high temperature annealing and γ-radiation effects on Optical Absorption (OA) and Electron Paramagnetic Resonance (EPR) properties. Chemical analysis revealed that besides Si, Al, Ca and Mg, other oxides i.e., Fe, Mn, Na, K, Ti and P are present in the structure as impurities. OA measurements of natural and annealed pumpellyite revealed several bands in the visible region due to spin forbidden transitions of Fe2+ and Fe3+. The behaviour of bands around 900 and 1060nm, with pre-annealing and γ radiation dose, indicating a transition Fe2+→e−+Fe3+. On the other hand, EPR measurements reveal six lines of Mn2+, and satellites due to hyperfine interaction, superimposed on the signal of Fe3+ around of g=2. For heat treatment from 800°C the signal grows significantly and for 900°C a strong signal of Fe3+ hides all Mn2+ lines. The strong growth of this signal indicates that the transitions are due to Fe3+ dipole–dipole interactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
