Agrellite is a rare inosilicate, having a crystal structure characterized by SiO4-tetrahedral tubes located between continuous wall layers formed by edge-sharing Ca-polyhedra. A detailed crystal chemical and physical study of agrellite specimens is carried out by means of electron probe microanalysis, Fourier transform infrared spectroscopy, electron-paramagnetic resonance, and single crystal X-ray diffraction. Additionally, the electronic structures of agrellite was calculated. Luminescence due to 5d-4f transition in Ce3+ ions is observed in both investigated samples. EPR analysis points out the Mn2+ replaces Ca2+ ion in Ca(1A) and Ca(2B) positions, coordinated by two F sites.
Spectroscopy and crystal chemical properties of NaCa2[Si4O10]F natural agrellite with tubular structure
Kaneva E.
;Mesto E.;
2020-01-01
Abstract
Agrellite is a rare inosilicate, having a crystal structure characterized by SiO4-tetrahedral tubes located between continuous wall layers formed by edge-sharing Ca-polyhedra. A detailed crystal chemical and physical study of agrellite specimens is carried out by means of electron probe microanalysis, Fourier transform infrared spectroscopy, electron-paramagnetic resonance, and single crystal X-ray diffraction. Additionally, the electronic structures of agrellite was calculated. Luminescence due to 5d-4f transition in Ce3+ ions is observed in both investigated samples. EPR analysis points out the Mn2+ replaces Ca2+ ion in Ca(1A) and Ca(2B) positions, coordinated by two F sites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
