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
503 2019-08-27 16:00  Rm. 1323, E6  Critical current properties of Fe-based superconductors file
502 2019-07-16 16:00  Rm. 1323 (E6-2)  2019 Physics Distinguished Lecture file
501 2019-08-19 10:00  Rm. 1322, E6-2  Tutorials on Multimode Quantum Optics in the Continuous Variable Regime file
500 2019-06-12 15:00  Rm# 1323, E6-2  The relation between free and interacting fermionic SPT phases file
499 2020-11-17 12:00  Online(Zoom)  Quantum- & Nano-Photonics" 세미나 시리즈 file
498 2021-04-02 14:30  Online(Zoom)  Quantum computing and entanglement generation using trapped ions and photons
497 2021-04-02 16:00  Online(Zoom)  Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
496 2020-11-26 16:00  Online(Zoom)  2020 가을학기 광학분야 특별세미나(Light Engineering Beyond the Diffraction Limit)
495 2021-03-25 16:00  Online Seminar (Zoom)  Search for dark matter axion with Rydberg atoms file
494 2022-05-27 11:00  Online seminar  Current Status and Future Plans of ADMX file
493 2022-04-15 11:00  Online seminar  (응집물리 세미나) First-principles studies of polar oxides and their applications file
492 2022-06-10 11:00  Online seminar  Record-quality two-dimensional electron systems file
491 2022-06-03 09:30  Online seminar  (Quantum-&Nano-Photonics Webinar) Seeing glass in a new light: reimagine chalcogenide photonics file
490 2022-03-18 11:00  Online seminar  (응집물리 세미나) Illuminating exotic states of matter: Raman spectroscopy as an experimental tool to characterize quantum spin liquids file
489 2021-05-14 14:30  Online seminar  Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
488 2021-07-29 14:00  Online seminar  Gravitationally Induced Dark Sector and Inflationary Dynamics file
487 2021-01-28 18:00  Online Seminar  Quantum metamaterials: concept, theory, prototypes and possible applications file
486 2021-06-11 14:30  Online seminar  Engineering sound waves and vibrations in multi-mode nanomechanical systems file
485 2021-06-11 16:00  Online seminar  Pseudogap in surface-doped black phosphorus file
484 2021-05-14 16:00  Online seminar  Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file