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)
574 2025-01-08 16:00  Dr. SangEun Han  Quantum impurity model for two-stage multipolar ordering and Fermi surface reconstruction
573 2024-12-17 15:00  Isaac H. Kim  Learning state preparation circuit for quantum phases of matter (Isaac H. Kim, UC Davis)
572 2024-12-06 16:00  Vladimir Y. Chernyak  Bright Squeezed Light (BSL) Spectroscopy with Interferometry from First Principles
571 2024-11-30 10:30  Joon Young Park  Towards probing topological phases in Corbino-geometry Josephson junctions on a topological insulator surface
570 2024-11-21 16:00  Prof. Ulrich Höfer  Time-resolved photoemission: From bandstructure to orbital movies file
569 2024-11-21 11:00  Daniel L. Jafferis  3d Gravity and Tensor Model file
568 2024-11-18 10:30    Manipulation of antiferromagnetic magnon polarization in synthetic antiferromagnets
567 2024-11-13 12:00    [11/13(수) 물리학과 세미나 안내] Separability as a window to mixed-state quantum phases and phase transitions / Tarun Grover (UC San Diego, Associate Professor)
566 2024-10-31 13:00    Mini-workshop on first-principles DFT methods and applications
565 2024-10-30 14:30    [Seminar Invitation] Mario Cuoco (CNR-SPIN, c/o University of Salerno, Fisciano, Italy) / 2024.10.30. 14:30 / E6-2, #3441
564 2024-10-21 13:00    [Physics Seminar] “Non-Hermitian Point-Gap Topology in Junction Systems” file
563 2024-10-17 16:00    Photonic Methods for Quantum Levitodynamics Beyond the Rayleigh Regime
562 2024-10-14 11:00    [RSVP, Oct 14th Mon] Ambassador of Hungary to Republic of Korea Special Lecture file
561 2024-10-02 12:00    Data-driven discovery of neural computations through brain-wide and cell-type-specific dynamical systems file
560 2024-09-26 14:00    Quantum spin nematic phase in a square-lattice iridate
559 2024-09-03 12:00    2024 가을학기 물리학과 특별세미나 전체 일정 (응집물리 및 광학분야) file
558 2024-09-02 16:00    2024학년도 가을학기 물리학과 콜로키움(Physics Colloquium) file
557 2024-08-22 16:00    [CAPP seminar] Development of a 12-20 GHz CO Intensity Mapping Receiver for Capturing the Star-formation History in the Early Universe file
556 2024-08-16 11:00    Cathodoluminescence for nanophotonics: Applications to plasmonic bandgap materials and perovskite semiconductors file
555 2024-08-14 11:00    Pair Density Waves and Supercurrent Diode Effect in Altermagnets