visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2018-06-22 16:00 
일시 June 22 (Fri.), 04:00 PM 
장소 #1323, E6-2 
연사 Dr. Daniel Sando 

Physics Seminar

 

 

Tuning functional properties of BiFeO3films using strain and growth chemistry

 

Dr. Daniel Sando

Univ. of New South Wales, Sydney

 

June 22 (Fri.), 04:00 PM

#1323, E6-2

 

Abstract:

Multiferroics – materials with coexisting ferroic orders such as ferroelectricity and (anti)-ferromagnetism – are presently under intense study by virtue of their promise in next-generation data storage devices. Bismuth ferrite (BiFeO3– BFO) is one of the very few that orders above room temperature. In the bulk, BFO is rhombohedral (R), and in thin films [1] its properties are sensitive to strain [2,3]. The discovery of the epitaxially-stabilized “super tetragonal phase” of BFO (T-BFO) [4] incited a flurry of research activity focused on understanding the phase transition and its possible functionalities [5]. T-BFO is also multiferroic, with large ferroelectric polarization and antiferromagnetic order [4], and the strain relaxation-induced T/R phase mixtures and their exceptional piezoelectric responses [6] continue to intrigue and motivate researchers. A particularly important characteristic of this phase mixture is the interconversion between the R,T phases with an applied electric field [6]. Since the oxygen configuration of the R and T polymorphs is different [5], the electronic, magnetic, and optical properties can thus be dynamically modulated. An additional rather crucial (and thus far underexplored) aspect of mixed R/T BFO is the role of chemistryin the formation of the metastable T-phase. Since T-BFO is typically fabricated by pulsed laser deposition, growth parameters can be used as a strong handle to tailor film properties and functionalities.

Here I will describe our work on understanding the influence of strain and growth conditions on the optical, magnetic, and ferroelectric properties of BFO films. I will also show that by precisely controlling fabrication conditions, the formation of the mixed R/T phases in BFO films can be completely suppressed for thicknesses above 70 nm. Such an intriguing result is useful for applications where thicker pure T-BFO films are needed, such as for measuring the expected giant polarization, or for precisely controlling the proportions of the various phases. Finally, through analysis of a large set of epitaxial films, it will be shown that the optical band gap of BFO is rather insensitive to a host of growth and processing parameters [7]. Combined with the numerous other functionalities of this material, one can envisage multifunctional devices, for example, that harvest mechanical and solar energy, or to enhance magnetoelectric coupling at these multiferroic phase boundaries.

References

[1] Sando et al., J. Phys: Condens. Matt. 26, 473201 (2014). 

[2] Infante et al., PRL 105, 057601 (2010). 

[3] Sando et al., Nat. Mater. 12, 641 (2013). 

[4] Bea et al., PRL 102, 217603 (2009). 

[5] Sando et al., Appl. Phys. Rev. 3, 011106 (2016). 

[6] Zeches et al., Science 326, 977 (2009). 

[7] Sando et al., Adv. Opt Mater. 6, 1700836 (2018).

 

 

 Department of Physics, KAIST

번호 날짜 장소 제목
282 2023-11-16 16:00  E6-2(Natural Science B/D). 1st fl. #1323  Electric-field control of emergent phenomena in correlated oxide thin films
281 2023-11-09 16:00  E6-2(Natural Science B/D). 1st fl. #1323  Assessing the Capability of Near-Term Photonic Devices Towards Quantum Supremacy
280 2016-09-02 14:30  E6-2(1st fl.), #1323  Nanoscale Thermal Physics: Seebeck Effect and Nanoscale Friction
279 2016-09-02 16:00  E6-2(1st fl) #1323  Quantum Electrical Transport in Topological Insulator Nanowires
278 2022-01-17 14:00  E6-2 Room 2502  Five Lectures on Observational Probes of Dark Energy file
277 2020-11-12 16:00  E6-2 1323  2020 가을학기 광학분야 특별세미나
276 2024-03-20 16:00  E6-2 #2502  [High-Energy Theory Seminar] Black hole states at finite N
275 2024-03-13 16:00  E6-2 #2502  [High-Energy Theory Seminar] The Schwarzschild Black Hole from Perturbation Theory to all Orders
274 2022-10-26 10:00  E6-2 #2502  Replica Higher-Order Topology of Hofstadter Butterflies in Twisted Bilayer Graphene
273 2022-08-08 14:00  E6-2 #2502  Classical Shadow Tomography for Analog Quantum Simulators
272 2023-07-14 11:00  E6-2 #1501  Interfaces engineering of thin film oxides
271 2016-09-29 16:00  E6-2 #1323 (1st floor)  Large-scale Silicon Photonic MEMS Switches
270 2022-11-24 16:00  E6-2 #1323 & Zoom  Probing fundamental physics by mapping the mm and sub-mm sky
269 2023-03-16 16:00  E6-2 #1323  (광학분야 세미나) Investigation of 3D cell mechanics using refractive-index tomography
268 2023-01-09 16:00  E6-2 #1323  Non-Hermitian Hopf-bundle Matter. Moon Jip Park (IBS-PCS)
267 2023-01-10 16:00  E6-2 #1323  Terahertz Spectroscopy of Quantum Materials, Jae Hoon Kim (Yonsei University)
266 2023-03-24 11:00  E6-2 #1323  (응집물리 세미나)Floquet simulators of topological surface states in isolation
265 2022-11-03 13:00  E6-2 #1323  [High-Energy Theory Seminar] Supersymmetric observables via Fermi-gas method
264 2023-04-06 16:00  E6-2 #1323  (광학분야 세미나)Nanophotonics-based approaches to explore Berry physics
263 2023-03-30 16:00  E6-2 #1323  (광학분야 세미나)Scalable quantum entanglement in trapped-ions based quantum computer