Electron spin resonance in glasses

Optical spectroscopy of Li2B4O7, CaB4O7 and LiCaBO3 borate glasses doped with europium

“…According to Refs. [36,37] -Fe 3+ centres coupled through a magnetic dipolar interaction [36]. The uncontrolled Fe 3+ impurity ions are characterized by very weak spin-forbidden absorption transitions in the UV and 'blue' spectral regions.…”

“…Up to now the optical and luminescent properties of crystalline and glassy Eu-doped borate compounds with different chemical compositions have been extensively investigated in a number of works [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Let us remind of the main results.…”

Role of oxygen on the dangling bond configuration of low oxygen content SiNx:H films deposited at room temperature

“…Among the various possibilities, the single line structure of the spectrum and its g value precludes assignation of the defect to oxygen-hole centers or peroxy radicals, as observed in a-SiO 2 . 8 Thus, these defects should correspond again to dangling bonds and should be associated to Si, because a N-dangling bond would produce a triplet structure in the line due to the HF interaction, 3 which has not been observed. Moreover, the small ⌬H value of the line cannot be accounted for if any of the three backbonds is saturated by N atoms, 3 i.e., the center should be of the form…”

EMR study and superposition model analysis of Cr3+ and Fe3+ impurity ions in mullite powders used in aerospace industry

“…Despite the similar chemical compositions of materials, differences between EMR spectra were detected. The analysis of the line positions suggests that the lines with g eff = 4.28 and g eff  2.00 may be attributed to Fe 3+ (S = 5/2) ions, because they present a typical spectrum for so-called disordered systems [12] that present a glassy host [13]. The line intensities decrease progressively showing the evolution of the relative line shapes and the intensities at g eff = 4.3 from isolated ions in local tetrahedral (and eventually octahedral) sites [13].…”