Role of crystal and magnetic structures in the magnetoelectric coupling in CaMn7O12

DOI: 10.1103/PhysRevB.109.054417

Authors: Jhuma Sannigrahi (Indian Institute of Technology Goa; ISIS Neutron and Muon Source) , Md Salman Khan (Sungkyunkwan University) , Mohamad Numan (Indian Association for the Cultivation of Science) , Manjil Das (Indian Association for the Cultivation of Science) , Anupam Banerjee (Indian Association for the Cultivation of Science) , Manh Duc Le (ISIS Neutron and Muon Source) , Giannantonio Cibin (Diamond Light Source) , Devashibhai Adroja (ISIS Neutron and Muon Source; University of Johannesburg) , Subham Majumdar (Indian Association for the Cultivation of Science)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 109

State: Published (Approved)
Published: February 2024
Diamond Proposal Number(s): 17752

Abstract: We investigate the magnetoelectric coupling in CaMn 7 O 12 (CMO) through a comprehensive spectroscopic analysis combining inelastic neutron scattering (INS), x-ray absorption spectroscopy (XAS), and synchrotron-based powder x-ray diffraction (PXRD). CMO's intricate interplay between magnetism and ferroelectricity is dissected to uncover its underlying mechanisms. XAS reveals a mixed valency of Mn ions in CMO, reflecting the presence of Mn 3 + and Mn 4 + ions, which contributes to its magnetoelectric properties. The double structure in Mn- K near-edge absorption spectra reinforces multiple Mn sites as well as the mixed valency of the compound. Synchrotron-based PXRD experiments conducted over a range of temperatures unveil structural distortions near the magnetic transition temperatures of CMO. These distortions coincide with anomalies in lattice parameters and bond lengths, shedding light on the link between structural modulations and magnetoelectric behavior. Furthermore, INS measurements identify specific energy bands ( E 1 , E 2 , and E 3 ) associated with distinct exchange interactions between Mn ions. This work advances our understanding of magnetoelectric coupling mechanisms and showcases the potential of multifunctional materials for applications in spintronics and related fields.

Journal Keywords: Electric polarization; Ferroelectricity; Magnetic interactions; Spin-phonon coupling; Multiferroics; Noncollinear magnets; Polycrystalline materials; Inelastic neutron scattering; X-ray absorption near-edge spectroscopy; X-ray powder diffraction

Diamond Keywords: Spintronics; Ferroelectricity

Subject Areas: Materials, Physics


Instruments: B18-Core EXAFS

Other Facilities: Indian Beam Line at Photon Factory; MERLIN at ISIS

Added On: 19/02/2024 09:47

Documents:
PhysRevB.109.054417.pdf

Discipline Tags:

Quantum Materials Multiferroics Physics Electronics Magnetism Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)