visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 #1323, E6-2 
일시 June 22 (Fri.), 04:00 PM 
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 일시 장소 연사 제목
공지 Sep.22 2022  E6-1 #1323    2022 가을학기 응집물리 및 광학 세미나 전체 일정
396 2014/05/28, PM5  KI Building, Matrix Hall  이웅범 대표이사(LG이노텍)  부품소재산업이 미래다
395 Nov. 25 (Fri), 11:00AM  E6-2 #1323  이승섭(서울대 물리천문학부 교수)  (응집물리 세미나) DMFT+ NRG: From models to real materials, from local to nonlocal correlations
394 3. 21(월),16:00  E6, #1501  이상성교수 (한국천문연구원)  Multi-wavelength Studies on Relativistic Jets from Gamma-ray Bright Active Galactic Nuclei
393 August 1, 2018 at 11:00AM  양분순 빌딩 (E16-1) 207호  이대열 교수, 예일대 석좌교수  Future of AI: Is the brain a computer? file
392 Sep. 23 (Fri.), 11:00AM  E6-2 #1323  이길호(포스텍 물리학과 교수)  (응집물리 세미나) Steady Floquet-Andreev states in graphene Josephson junctions file
391 Sep. 11(Fri), 14:00~  zoom  이관형교수/SNU, 이상윤교수/GIST  SRC Seminar file
390 Nov. 24 (Thu) 2022, 4:00PM  E6-2 #1323  유정완(기초과학연구원, Center for Theoretical Physics of Complex Systems 교수)  (광학분야 세미나) Non-Hermitian physics and non-Hermitian singularity
389 5. 2(월),16:00  E6, #1501  유상운교수 (한밭대)  What can we learn from the history of science and technology?(우리말강의)
388 4pm, 28th April  E6 1323  유경식 (KAIST 전기및전자공학부)  (광학분야 특별세미나)Adiabaticity and symmetry in optical waveguide design
387 2009/02/23-05/04  E6, 1501  안종현교수(성균관대) 외  Physics Colloquium : 2009 Spring file
386 2014/03/10-06/09  E6, 1501  신용일교수(서울대)  Physics Colloquium : 2014 Spring file
385 4pm, 14th April  E6 1323  신승우 (KAIST 물리학과)  (광학분야 특별세미나)Holographic tomography of dielectric tensors at optical frequency
384 Nov. 11 (Fri), 11:00AM  E6-2 #1323  손창희(UNIST 물리학과 교수)  (응집물리 세미나) Honeycomb oxide heterostructures for quantum spin liquid
383 3. 7(월),16:00`  E6, #1501  손석우교수 (서울대 지구환경과학부)  Climate Physics and Modelling(우리말강의)
382 Aug. 1st(Mon), 10:00AM  E6 #1501 & Zoom  손상모 박사(Space Telescope Science Institute (STScI)  [Update 세미나 영상] James Webb Space Telescope & OTE Commissioning
381 Oct. 27 (Thu), 4:00PM  E6-2 #1323  서준호(한국표준연구원 박사)  (광학분야 세미나) Cavity optomechanical systems for quantum transduction
380 2011/05/16, 4PM  E6, 1501  서민교교수(KAIST)  Photonics with surface plasmon polaritons
379 5월 17일(화), 11:00 ~ 12:00  창의학습관(E11), 406호  방준혁 박사(Korea Basic Science Institute, KBSI)  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
378 2013/09/09-12/09  E6, 1501  박혁규교수(부산대) 외  Physics Colloquium : 2013 Fall
377 April 6 (Fri.), 10:00 AM  #2502, E6  박채연 박사  Entanglement and thermalization in many-body systems: recent progress file