• Spectroscopy and Spectral Analysis
  • Vol. 40, Issue 2, 415 (2020)
WANG Shi-xia* and GAO Jin-jin
Author Affiliations
  • [in Chinese]
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    DOI: 10.3964/j.issn.1000-0593(2020)02-0415-05 Cite this Article
    WANG Shi-xia, GAO Jin-jin. Study on the Influence of Pb Doping on High Pressure Structural Properties of Tin Dioxide Using Diamond Anvil Cell and Raman Spectra[J]. Spectroscopy and Spectral Analysis, 2020, 40(2): 415 Copy Citation Text show less

    Abstract

    Based on the stable molecular structure and physicochemical property, SnO2 has been more and more useful in the field of optical, electrical and magnetic materials in recent years. In order to broaden the application of SnO2, the research focused on the phase transition behavior of pure SnO2 and SnO2 doped by lead ions under high pressure, and the changes of Raman spectrum active vibration modes were investigated at the same time. The pure SnO2 and SnO2 doped by lead ions with 10% content were prepared by hydrothermal method. And the Scanning Electron Microscopy (SEM) images and X-ray diffraction (XRD) patterns of samples were measured. SEM images showed that samples were arranged as divergent nanorods which from the center to form a whole flower-like shape. XRD patterns showed that the crystal structure of samples was rutile tin dioxide (space group is P42) at room temperature and pressure. In this paper, the high pressure phase transition processes of materials rutile tin dioxide and SnO2 doped by lead ions with 10% content were investigated by using Mao-Bell Diamond anvil cell and in situ Raman spectroscopy. The results showed the active Raman modes (B1g, Eg, A2g, B2g) of pure SnO2 and SnO2 doped by lead ions all moved to high frequencies when the pressure was added to 26 GPa. The Eg peak of pure SnO2 split and a new peak appeared in 563 cm-1 when the pressure was added to 14GPa, which indicated that SnO2 transformed from tetragonal rutile structure to CaCl2 structure. The Raman peak of 577 cm-1 happened in the sample SnO2 doped by lead ions in room pressure, and the vibration mode of B1g changed to Ag mode when the pressure was addeda to 13 GPa which indicated the first-order phase transition of SnO2 doped by lead ions. Compared to pure SnO2, SnO2 doped by lead ions had a lower first-order phase transition pressure, which were attributed to the fact that lead ions replace tin ions in SnO2 cells. The spacing between atoms decreased and surface defects of valence difference happened after doping, which caused the decrease of structural stability of SnO2 and the decrease of phase transition pressure. In addition, the characteristic peaks at 577 and 639 cm-1 of SnO2 doped by lead ions began to coalesce into cladding peaks and its symmetry decreased when the pressure was added to 12 GPa, which indicated that the disorder degree of atoms on the surface of crystals increased and transition process from crystals to amorphous crystals occurred. The characteristic peaks of the two materials disappeared when the pressure reached to 26 GPa, and no other characteristic peaks were observed. Non-hydrostatic pressure in this research had a certain effect on the phase transformation pressure. The large stress at the grain boundary made nanocrystals form to nucleation point of high-pressure phases more easily, which might reduce the phase transformation pressure and cause some crystals tend to be amorphous more easily. In summary, the phase transition behavior of pure SnO2 and SnO2 doped by lead ions on different pressure conditions were studied, which enriched the diversity of physical and chemical properties of SnO2 under extreme conditions.
    WANG Shi-xia, GAO Jin-jin. Study on the Influence of Pb Doping on High Pressure Structural Properties of Tin Dioxide Using Diamond Anvil Cell and Raman Spectra[J]. Spectroscopy and Spectral Analysis, 2020, 40(2): 415
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