Professor Ji Young Jo's research team has developed multi-stiffness electric and magnetic property control technology

□ A method to control the electrical and magnetic properties of multiple stiff materials has been discovered, making it one step closer to the development of next generation electronic devices. A research team led by Professor Ji Young Jo (Gwangju Institute of Science and Technology), Ph.D. student Sung Su Lee (Gwangju Institute of Science and Technology), and Professor Young-Min Kim (Sungkyunkwan University) have identified the principle of ferroelectricity and ferromagnetism in multiple rigid films. 

□ Multiple stiffness is a property having both ferroelectric and ferromagnetic properties. The ferroelectric material forming the electric field is used for computer memory chips, capacitors, and the like. Multiple stiffness, which has both properties, is expected to be developed as a new concept with research being carried out to create new materials and devices.

 

□ The researchers found that it is possible to simultaneously control ferroelectricity and ferromagnetism by artificially controlling the oxygen atom position of bismuth iron oxide (BiFeO3) * thin films.

* BiFeO3: One of the most studied multiple stiffness material that shows multiple stiffness at room temperature as a thin film  and was reported in 2003 to have very high ferroelectricity. These special properties are expected to make it an important candidate for next-generation memory materials.

□ The researchers have also developed high quality thin film technology to increase the thickness of thin films that can control oxygen atom position with 10 times more precision. As a result, the researchers succeeded in doubling ferroelectricity and ferromagnetic properties.

□ Professor Ji Young Jo said, "Until now, it has been difficult to measure ferroelectricity and ferromagnetism because it was only possible to control the oxygen atom position at the interface area, which is several nanometers or less, and thus limiting its applicability as an electronic device. In this study, the magnitude of ferroelectricity and ferromagnetism is improved and controllable, which greatly enhances the applicability of multiple stiffness materials."

□ This research was conducted jointly with Dr. Tae Yeong Koo (Pohang Accelerator Laboratory), Professor Yunseok Kim (Sungkyunkwan University), Professor Beongki Cho (Gwangju Institute of Science and Technology), and Jun Hee Lee (Ulsan National Institute of Science and Technology).

□ This research was supported by the National Research Foundation (NRF) with support from the Engineering Basic Research Support Project (Ministry of Education), Future Material Discovery Project and National Strategic Project (Ministry of Science and Technology, Ministry of Information and Communication), and POSCO TJ Park Foundation Cheongam Science Fellowship. This research was published as a Frontpiece on March 26, 2018 in Advanced Functional Material, which has an impact factor of 12.12.