Structural and 119Sn Mössbauer study of Hf1-xSnxO2.

In the present work, we report the preparation and study of tin (Sn) substituted polycrystalline HfO₂, which is known for its fascinating ferroelectric properties. Hf_1-xSn_xO₂ (x=0 to 0.1) are prepared by conventional solid state reaction method and characterized by x-ray diffraction (XRD), Raman spectroscopy, 119 Sn Mössbauer spectroscopy and dielectric / ferroelectric measurements. XRD of all the samples is analyzed considering P2₁/c (monoclinic) space-group, however less intense un-reacted SnO₂ peaks were observed for x ≥ 3% substitution. Raman spectra of all the samples is observed to be characteristic of P2₁/c phase. The 119 Sn Mössbauer spectra show a broad absorption line and the obtained hyperfine parameters are more or less same for all the compositions studied, within the experimental error, indicating the presence of parent P2₁/c phase with Sn substitution. No switchable polarization is observed from bulk ferroelectric measurements, corroborating the observed XRD, Raman and Mössbauer results i.e., the presence of only P2₁/c (monoclinic) phase. The present results are discussed in the context of recent theory works in HfO₂. [ABSTRACT FROM AUTHOR]