# Two displacive ferroelectric phase transitions in multiferroic quadruple perovskite Bi Mn 7 O 12 https://mdr.nims.go.jp/datasets/ebcf9e22-9895-4c7c-a408-1a6dd2d214fa ## File - [PhysRevB.109.134111.pdf](https://mdr.nims.go.jp/filesets/a8c0f085-87ff-4ec0-bc8c-25d1fb16b424/download) ([Detail](https://mdr.nims.go.jp/filesets/a8c0f085-87ff-4ec0-bc8c-25d1fb16b424.md)) ## Id ebcf9e22-9895-4c7c-a408-1a6dd2d214fa ## Local identifier ## Visibility open_to_public ## State published ## Created at 2024-05-01T06:01:04.835213Z ## Updated at 2024-05-02T07:30:12.847056Z ## Published at 2024-05-02T07:30:13.259829Z ## Doi ## First published url https://doi.org/10.1103/physrevb.109.134111 ## Date published 2024-04-25 ## Recorded date published 2024-4 ## Resource type journal_article ## Manuscript type vor ## Collection ## Title - title: "Two displacive ferroelectric phase transitions in multiferroic quadruple perovskite \nBiMn7O12" title_type: original lang: en ## Description - description: We report on the microwave, terahertz (THz), infrared and Raman spectroscopic studies of BiMn7O12 ceramics, shedding more light into the nature of two structural phase transitions and their possible relation with ferroelectricity in this compound. We observed a softening of one polar phonon in the THz range on cooling towards 460 and 300 K, i.e., temperatures at which BiMn7O12 undergoes subsequent structural phase transitions from monoclinic I2/m to polar monoclinic Im and triclinic P1 phases. The soft phonon causes dielectric anomalies typical for displacive ferroelectric phase transitions. Microwave measurements performed at 5.8 GHz up to 400 K qualitatively confirmed not only the dielectric anomaly at 300 K, but also revealed two other weak dielectric anomalies near the magnetic phase transitions at 60 K and 28 K. This evidences the multiferroic nature of the low-temperature phases, although the relatively high conductivity in the kHz and Hz spectral range prevented us from directly measuring the permittivity and ferroelectric polarization. Some Raman modes sense the magnetic phase transitions occurring near 60 and 25 K, showing that spin-phonon coupling is relevant in this compound and in this temperature range. The deviation of the Mn-O stretching mode frequency from the anharmonic temperature behavior was successfully explained by the spin correlation function calculated from the magnetic contribution to the specific heat. description_type: abstract lang: und ## Creator - name: A. Maia role: author orcid: https://orcid.org/0000-0002-0582-7272 - name: M. Kempa role: author orcid: https://orcid.org/0000-0002-5902-7780 - name: V. Bovtun role: author orcid: https://orcid.org/0000-0002-2470-6767 - name: R. Vilarinho role: author orcid: https://orcid.org/0000-0001-6104-9834 - name: C. Kadlec role: author orcid: https://orcid.org/0000-0003-2820-4462 - name: J. Agostinho Moreira role: author orcid: https://orcid.org/0000-0003-4659-7503 - name: A. A. Belik role: author orcid: https://orcid.org/0000-0001-9031-2355 - name: P. Proschek role: author orcid: https://orcid.org/0000-0003-2627-3544 - name: S. Kamba role: author orcid: https://orcid.org/0000-0003-4699-869X ## Contact agent ## Publisher organization: American Physical Society (APS) ## Managing organization ## Keyword - subject: BiMn7O12 schema: not_defined - subject: perovskites schema: not_defined - subject: multiferroic schema: not_defined - subject: ferroelectric transition schema: not_defined ## Rights - identifier: http://rightsstatements.org/vocab/InC/1.0/ ## Other identifier(s) ## Data origin ## Embargo ## Journal - title: Physical Review B issn: '24699950' volume: '109' issue: '13' article_number: '134111' ## Conference ## Related item ## Funding - identifier: 2/0137/19 funder_name: Vedecká Grantová Agentúra MŠVVaŠ SR a SAV - identifier: 21–06802S funder_name: Grantová Agentura České Republiky ## Instrument ## Instrument operator ## Instrument managing organization ## Measurement method ## Specimen ## Chemical composition ## Structure for specimen ## Structural feature for specimen ## Specific property for specimen ## Process for specimen treatment ## Computational method ## Energy level/transition state ## Software ## Custom property ## Fileset - id: a8c0f085-87ff-4ec0-bc8c-25d1fb16b424 filename: PhysRevB.109.134111.pdf content_type: application/pdf size: 2187168 md5: d28fef49f58151ab76a76f70754dc90e ## Thumbnail fileset_id: a8c0f085-87ff-4ec0-bc8c-25d1fb16b424 filename: PhysRevB.109.134111.pdf