Abstract
According to previous theoretical work, the binary oxide CuO can become a room-temperature multiferroic via tuning of the superexchange interactions by application of pressure. Thus far, however, there has been no experimental evidence for the predicted room-temperature multiferroicity. Here, we show by neutron diffraction that the multiferroic phase in CuO reaches 295 K with the application of 18.5 GPa pressure. We also develop a spin Hamiltonian based on density functional theory and employing superexchange theory for the magnetic interactions, which can reproduce the experimental results. The present Letter provides a stimulus to develop room-temperature multiferroic materials by alternative methods based on existing low temperature compounds, such as epitaxial strain, for tunable multifunctional devices and memory applications.
| Original language | English |
|---|---|
| Article number | 217601 |
| Journal | Physical Review Letters |
| Volume | 129 |
| Issue number | 21 |
| DOIs | |
| State | Published - Nov 18 2022 |
| Externally published | Yes |
Funding
We would like to thank Takayuki Harada of the National Institute for Materials Science for fruitful discussion, and J\u00E9r\u00F4me Debray and Claire V. Colin of the Institut N\u00E9el/CNRS for their technical support in cutting and polishing the crystals for the present neutron diffraction experiment. We acknowledge the STFC access to neutron beamtime. Raw data from the experiment can be obtained from. This work was supported by JSPS KAKENHI Grants No. 15H05433, No. 17KK0099, and No. 22H00297), JST-Mirai Program Grant No. JPMJMI18A3, Japan, the program AAAA-A18-118020190095-4 (Quantum), and the TUMOCS project, which has received funding from the European Union Horizon 2020 Research and Innovation Program under the Marie Sklodowska-Curie Grant Agreement No. 645660. We also would like to acknowledge the financial support from the Engineering and Physical Sciences Research Council, United Kingdom and Oxford-ShanghaiTech collaboration project.