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.
Original language | English |
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Article number | 041112 |
Journal | Physical Review B |
Volume | 97 |
Issue number | 4 |
DOIs | |
State | Published - Jan 19 2018 |
Funding
Research at ORNL was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. The work at Rutgers University was supported by the DOE under Grant No. DE-FG02-07ER46382. J.C.W. and J.M.S. acknowledge support from China Scholarship Council. This work has been partially supported by U.S. DOE. ORNL is managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy. Research at ORNL was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. The work at Rutgers University was supported by the DOE under Grant No. DE-FG02-07ER46382. J.C.W. and J.M.S. acknowledge support from China Scholarship Council. This work has been partially supported by U.S. DOE. ORNL is managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy.