• R S Ninghthoujam

Articles written in Pramana – Journal of Physics

• Finding confined water in the hexagonal phase of Bi0.05Eu0.05Y0.90P$O$_{4}·𝑥H2O and its impact for identifying the location of luminescence quencher

1H MAS NMR spectra of Bi0.05Eu0.05Y0.90PO4·𝑥H2O show chemical shift from −0.56 ppm at 300 K to −3.8 ppm at 215 K and another one at 5–6 ppm, which are related to the confined or interstitial water in the hexagonal structure and water molecules on the surface of the particles, respectively. Negative value of the chemical shift indicates that H of H2O is closer to metal ions (Y3+ or Eu3+), which is a source of luminescence quencher. H coupling and decoupling 31P MAS NMR spectra at 300 and 250 K show the same chemical shift (−0.4 ppm) indicating that there is no direct bond between P and H. It is concluded that the confined water is not frozen even at 215 K because of the less number of H-bonding.

• # Pramana – Journal of Physics

Volume 96, 2022
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019