Temperature dependent X‐ray diffraction and Raman spectroscopy studies of polycrystalline YCrO 3 ceramics across the T C ~ 460 K

In this paper, we report the X‐ray diffraction studies over the temperature range of 300–900 K and subsequent Rietveld refinement of the diffraction patterns shows that there is no evidence of any structural phase transition in YCrO 3 (YCO) across the paraelectric to ferroelectric phase transitions ( T C ~ 460 K), and the material retains the orthorhombic structure with Pnma space group. However, a detailed analysis reveals local distortions in the CrO 6 octahedra. To probe the local structural distortion, we have carried out temperature‐dependent, unpolarized Raman measurements, from 300 to 600 K. YCrO 3 shows a strong anomalous deviation in both phonon wavenumbers and line widths around T C . YCrO 3 is reported to possess as an incipient ferroelectric material to show that there are two competing phenomenon—onset of ferroelectricity due to rotation of CrO 6 octahedra and displacement of Y atom leading to suppression of ferroelectricity. This competition reveals that although the octahedral rotations favor a lower symmetry state, the Y atom displacement opposes it leaving YCO to exhibit only an incipient ferroelectric state. These results while being in agreement with the earlier theoretical predictions can also help suggest a pathway to a more stable ferroelectric state in these oxides by using a larger cationic substitution at the Y site.