Raman spectroscopy and electron-phonon coupling in Eu3+ doped Gd2Zr2O7 nanopowders

The Raman spectra of Eu3+ doped Gd2Zr2O7 nanopowders were measured. We registered three phonons at 177 cm(-1), 268 cm(-1), and 592 cm(-1), as well as their overtones at 354 cm(-1), 445 cm(-1), 708 cm(-1), 1062 cm(-1), 1184 cm(-1),similar to 1530 cm(-1), and similar to 1720 cm(-1). The phonon at 592 cm(-1) is known to be characteristic for Gd2Zr2O7 fluorite-type structure; however, the other two have not been registered so far. We found that the position of the newly detected phonons agrees well with the observed electron-phonon interaction. On the other hand, the registered multiphonon processes were a consequence of miniaturization that further induced changes in electronic structure of Eu3+ doped Gd2Zr2O7 nanopowders. (C) 2017 Elsevier B.V. All rights reserved.