- By:
- Tian, Wei ; Hoffmann, Christina M; Molaison, Jamie J; Moreira dos Santos, Antonio F; Matsuda, Masaaki ; Chakoumakos, Bryan C; Ye, Feng ; Fernandez-Baca, Jaime A; Tong, Xin ; Wang, Jinchen ; Sheng, Jieming ; Gao, Bin; Kim, Jae-Wook; Cheong, Sang-Wook
- Journal Name:
- Physical Review B
- Page Number:
- 41112
- Volume:
- 97
- Issue Number:
- 4
- Publication Date:
- November 9, 2023
- View DOI Listing:
- https://doi.org/10.1103/PhysRevB.97.041112
Abstract
We report a single crystal neutron and x-ray diffraction study of the hybrid improper multiferroic Ca3Mn1.9Ti0.1O7 (CMTO), a prototypical system where the electric polarization arises from the condensation of two lattice distortion modes. With increasing temperature (T), the out-of-plane, antiphase tilt of MnO6 decreases in amplitude while the in-plane, in-phase rotation remains robust and experiences abrupt changes across the first-order structural transition. Application of hydrostatic pressure (P) to CMTO at room temperature shows a similar effect. The consistent behavior under both T and P reveals the softness of antiphase tilt and highlights the role of the partially occupied d orbital of the transition-metal ions in determining the stability of the octahedral distortion. Polarized neutron analysis indicates the symmetry-allowed canted ferromagnetic moment is less than the 0.04μB/Mn site, despite a substantial out-of-plane tilt of the MnO6 octahedra.
