biostudies-literatureZhao JNational Science Foundation of China | National Natural Science Foundation of China-Yunnan Joint FundNational Science Foundation of China | National Natural Science Foundation of China-Yunnan Joint Fund (NSFC-Yunnan Joint Fund)747https://www.ebi.ac.uk/biostudies/studies/S-EPMC7854592biostudies-literatureUnknown12(1)The simple ABO<sub>3</sub> and A-site-ordered AA'<sub>3</sub>B<sub>4</sub>O<sub>12</sub> perovskites represent two types of classical perovskite functional materials. There are well-known simple perovskites with ferroelectric properties, while there is still no report of ferroelectricity due to symmetry breaking transition in A-site-ordered quadruple perovskites. Here we report the high pressure synthesis of an A-site-ordered perovskite PbHg<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub>, the only known quadruple perovskite that transforms from high-temperature centrosymmetric paraelectric phase to low-temperature non-centrosymmetric ferroelectric phase. The coordination chemistry of Hg<sup>2+</sup> is changed from square planar as in typical A-site-ordered quadruple perovskite to a rare stereo tNature communicationsA combinatory ferroelectric compound bridging simple ABO<sub>3</sub> and A-site-ordered quadruple perovskite.PMC785459211820101003Cao LYu RHu ZZhang JRen YGao JLiu QHuang QGreenblatt MLong YJin CChen CTDeng ZTjeng LHWang XZhao JShen XDong CDuan LRen CLi WQian YLi ZZhu JWeng HLin HJWeng SCfalseA combinatory ferroelectric compound bridging simple ABO<sub>3</sub> and A-site-ordered quadruple perovskite.The simple ABO<sub>3</sub> and A-site-ordered AA'<sub>3</sub>B<sub>4</sub>O<sub>12</sub> perovskites represent two types of classical perovskite functional materials. There are well-known simple perovskites with ferroelectric properties, while there is still no report of ferroelectricity due to symmetry breaking transition in A-site-ordered quadruple perovskites. Here we report the high pressure synthesis of an A-site-ordered perovskite PbHg<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub>, the only known quadruple perovskite that transforms from high-temperature centrosymmetric paraelectric phase to low-temperature non-centrosymmetric ferroelectric phase. The coordination chemistry of Hg<sup>2+</sup> is changed from square planar as in typical A-site-ordered quadruple perovskite to a rare stereo t2021-01-01T00:00:00Z2021 Feb2025-06-01T00:30:57.494Z2025-06-01T00:30:57.494ZS-EPMC78545923353148010.1038/s41467-020-20833-6