Coupled Lattice Polarization and Ferromagnetism in Multiferroic NiTiO ₃ Thin Films

Journal Article · Thu Jun 22 04:00:00 EDT 2017 · ACS Applied Materials and Interfaces

DOI:https://doi.org/10.1021/acsami.7b04481· OSTI ID:1372003

Varga, Tamas; Droubay, Timothy C.; Kovarik, Libor; Nandasiri, Manjula I. ^[1]; Shutthanandan, Vaithiyalingam; Hu, Dehong; Kim, Bumsoo ^[2]; Jeon, Seokwoo ^[3]; Hong, Seungbum ^[2]; Li, Yulan; Chambers, Scott A.

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1. Imaging and Chemical Analysis Laboratory, Montana State University, Bozeman, Montana 59717, United States
2. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea
3. Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea

Polarization-induced weak ferromagnetism has been predicted recently in LiNbO3-type MTiO3 (M = Fe, Mn, Ni). While coexisting ferroelectric polarization and ferromagnetism have been demonstrated in this family before, first in bulk FeTiO3, then in thin-film NiTiO3, the coupling of the two order parameters has not been confirmed. Here we report the stabilization of polar, ferromagnetic NiTiO3 by oxide epitaxy on LiNbO3 substrate utilizing tensile strain, and demonstrate the theory-predicted coupling between its polarization and ferromagnetism by x-ray magnetic circular dichroism under applied fields. The experimentally observed direction of ferroic ordering in the film is supported by simulation using phase-field approach. Our work validates symmetry-based criteria and first-principles calculations of the coexistence of ferroelectricity and weak ferromagnetism in MTiO3 transition metal titanates crystallizing in the LiNbO3 structure. It also demonstrates the applicability of epitaxial strain as a viable alternative to high-pressure crystal growth to stabilize metastable materials, and a valuable tuning parameter to simultaneously control two ferroic order parameters to create a multiferroic.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1372003
• Report Number(s): PNNL-SA-121771; 48108; 48647; KP1704020
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 26 Vol. 9; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Environmental Molecular Sciences Laboratory