Octahedral tilting dominated phase transition in compressed double perovskite Ba₂SmBiO₆

The comprehension of structural behaviors in double perovskites is crucial for their functional optimization, especially when applying external regulations. Here, to inquire about potential structures with better magnetic performance, high-pressure phase transformation perovskite Ba2SmBiO6 was first investigated up 50 GPa via situ x-ray diffraction and Raman spectroscopy. A pressure-induced transition from cubic Fm-3m orthorhombic Pnma discovered at 4.8 GPa, accompanied by the splitting peaks. Above 19.8 new becomes distorted as shown peak recombination broadening. variation spectra also confirms formation distortion during compression, through evolution Bi–O stretching, bending, octahedral rotation, Ba-sites translation modes. analysis tilt angles factor evinced that BiO6 tilting key occurrence. Based on Mulliken populations analyses, bonds undergo a covalent-ionic-antibonding across under compression. Our exploration mechanism guides modulation electronic properties extreme conditions.