visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2018-06-22 16:00 
연사  
장소 #1323, E6-2 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
566 2025-04-03 16:00  윤홍 박사 (Corning Technology Center Korea)  Introduction of Corning Glass Innovation file
565 2025-05-26 16:00  윤석호 박사(삼성종합기술원)  Photonics in the Age of AI: Industry Trends and Perspectives file
564 2023-03-17 11:00    (응집물리 세미나)Operando electron microscopy investigation of domain dynamics in twisted van der Waals materials file
563 2025-05-22 16:00  유현승 박사(삼성종합기술원)  Reconstructing Reality: Learning-based Methods for 3D Imaging and Graphics file
562 2022-12-07 16:00    (광학분야 세미나) Non-Hermitian physics and non-Hermitian singularity
561 2022-05-02 16:00    What can we learn from the history of science and technology?(우리말강의)
560 2022-04-28 16:00    (광학분야 특별세미나)Adiabaticity and symmetry in optical waveguide design
559 2025-04-11 11:00  옥종목 교수 (부산대학교 물리학과)  An Approach to Controlling Physical Properties:Defect-Engineered High-Quality Single Crystal Growth file
558 2025-01-23 14:00  여영기 박사  Complete Polytype switching by super lubricant van der Waals cavity arrays file
557 2024-04-19 15:00    Engineering Physics for Semiconductor Equipment Innovation file
556 2009-02-23 16:00    Physics Colloquium : 2009 Spring file
555 2014-03-10 16:00    Physics Colloquium : 2014 Spring file
554 2022-04-14 16:00    (광학분야 특별세미나)Holographic tomography of dielectric tensors at optical frequency
553 2022-11-11 11:00    [Update 세미나영상] (응집물리 세미나) Honeycomb oxide heterostructures for quantum spin liquid file
552 2022-03-07 16:00    Climate Physics and Modelling(우리말강의)
551 2022-08-01 10:00    [Update 세미나 영상] James Webb Space Telescope & OTE Commissioning
550 2022-10-27 16:00    (광학분야 세미나) Cavity optomechanical systems for quantum transduction
549 2011-05-16 16:00    Photonics with surface plasmon polaritons
548 2016-05-17 11:00    The CERN Resonant WISP Search: Development, Results and Lesson-Learned
547 2013-09-09 16:00    Physics Colloquium : 2013 Fall