Study of electron band structure of Pr doped ZnAl2O4 by reducing background in modified-CDB-spectroscopy

Ghasemifard, Mahdi; Ghamari, Misagh; Izi, Meisam

doi:10.1016/j.radphyschem.2023.110800

Cited by 3 publications

(1 citation statement)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 As shown in Figure 1, parameters S and W are respectively defined as the ratio of the area of the central part of the spectrum (small linear momentum) and the ratio of the area of the areas with high momentum (tail of the spectrum or areas far from the center of the spectrum) to the total area of the CDBS spectrum. 6 Another method of CDBS spectrum analysis is to consider spectral data in the form of normalized count ratio in each channel to their corresponding number in the reference sample spectrum. In this study, pure aluminum metal was chosen as the reference because the high purity of the reference sample is very important to reduce the background effects in the tail regions of the spectrum.…”

Section: Coincidence Doppler Broadening Spectroscopymentioning

confidence: 99%

Characterization of polar groups in polyvinyl chloride–ethyl vinyl acetate blends using coincidence Doppler broadening spectroscopy

Ghasemifard,

Ghamari

2023

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

Coincidence Doppler broadening spectroscopy (CDBS), known for its exceptional precision, is extensively employed in examining the electronic states of polymers. In this study, polyvinyl chloride (PVC)–ethyl vinyl acetate (EVA) polymers blends were prepared using conventional techniques, following specific ratios (75:25, 50:50, and 25:75, respectively). Spectroscopic analysis reveals that the longitudinal component of linear momentum surpasses the momentum unit (i.e., 10−3 m0c) when considering the ratio curve associated with the participation of oxygen core electrons. When compared to non‐polymer samples, the PVA polymer and PVA–EVA polymer blend exhibit greater free volume voids in contrast to non‐polymer structural defects. Furthermore, the annihilation of ortho‐positronium with core electrons, likely EVA oxygen core electrons, contributes to the measured free volume voids. An increased annihilation of positrons or positroniums by oxygen in the CDBS spectrum leads to higher calculated W parameter values. Conversely, as the PVC content increases, the W parameter decreases, suggesting reduced ortho‐positronium annihilation and consequently, enhanced formation of para‐positronium in the overall annihilation process. In summary, this investigation demonstrates the utility of CDBS in elucidating the electronic states and free volume voids in PVC and EVA polymers.

show abstract

Section: Coincidence Doppler Broadening Spectroscopymentioning

confidence: 99%