Infrared and Raman spectra of the spinel ZnGa₂O₄

Abstract

A study of the infrared and Raman spectra of single crystals and powders of ZnGazOe yields the following k = O phonon frequencies: 175 cm-I (TlU), 328 cm-l (Tiu), 420 cm-l (Tiu), 570 cm-l (TlU), 467 cm-l (TzS), 611 cm-l ( T z~) , 638 cm-l (Eg) and 714 cm-l ( A I~) .The results are compared with the frequencies of the vibronic sidebands of the Cr3+ R line emission as observed in ZnGazO4: Cr3+. It is found that the strongest vibronics of the R lines are due to coupling of the Cr3+ electrons with the TllL modes of the ZnGazOe lattice, especially with the two higher frequency Tllc modes.

Eu+3 and Cr+3 doping for red cathodoluminescence in ZnGa2O4

“…8 This is consistent with the Frohlich interaction that says that charged carriers couple better to LO phonons than transverse optical (TO) phonons. The broad peak shape is due to vibronic structure at both higher energy (phonon destruction) and at lower energy (phonon creation).…”

Novel Self‐Activated Zinc Gallogermanate Phosphor: The Origin of its Photoluminescence

“…10 The other two peaks at 610 and 714 cm À1 are assigned to the [Ga-O-Zn] modes. 11 When x < 0.5, the structure is predominated by the [Ga-O-Zn] modes, and gradually replaced by the [Ge-O-Zn] modes and [GeO 4 ] tetrahedra as x is over 0.5. The structure evolution coincides with the compositional variation of the XRD patterns.…”

Enhancement of photoluminescence, persistent luminescence and photocatalytic activity in ZnGa2O4 phosphors by lithium ion doping

“…The Raman peaks at 545 cm À1 and 670 cm À1 assign as the second order Raman lines which arise from disordered structure. As already known, the first order Raman active modes in spinel ZnGa 2 O 4 are attributed to Zn 2+ ions in the tetrahedral sites, and have no relation with motions of the octahedral Ga 3+ sites [15]. Thus, only O 2À ions and Zn 2+ ions in the tetrahedral sites contribute to the first order Raman modes.…”