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
471 2023-06-08 16:00  E6-2, #1323  Thermal decoupling in high-Tc cuprate superconductors
470 2023-06-01 16:00  E6-2, #5301  Hall viscosity and topological phenomena
469 2023-06-01 16:00  E6-2 #1323  (광학분야 세미나)Quantum sensing using a squeezed light from hot Rb vapor
468 2023-05-31 16:00  E6-2, #2502  [High-Energy Theory Seminar] Resurgence and complex Chern-Simons theory
467 2023-05-26 11:00  E6-2 #1323  (응집물리 세미나)Spectral Analyses of Stochastic Charge Trapping in Oxide Heterostructures file
466 2023-05-22 13:00  E6-6 119  Design & Development of Electrochemical Biosensors for the Detection of T2DM Biomarkers
465 2023-05-19 11:00  E6-2 #1323  (응집물리 세미나)Dipole condensations in Tilted Bose-Hubbard Chains
464 2023-05-18 16:00  E6-2 #1323  (광학분야 세미나)Dielectric metasurfaces for optimized optical system and spatial light modulators
463 2023-05-17 16:30  Zoom  Detecting Hidden Photon Dark Matter via the Excitation of Qubits file
462 2023-05-17 14:00  E6 #1323  Optical Response in the multilayer thin films
461 2023-05-15 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  Role of dark Higgs boson in DM physics and cosmology file
460 2023-05-12 11:00  E6-2 #1323  (응집물리 세미나)Interlayer conductivity and plasmon in weakly coupled layered systems
459 2023-05-03 16:00  E6-2, #2502  Probing microscopic origins of axions by the chiral magnetic effect
458 2023-04-28 11:00  E6 #1323  Tkachenko wave: From the modern field theory viewpoint
457 2023-04-27 16:00  E6-2 #1323  (광학분야 세미나)On-chip spectrometers based on CMOS image sensors
456 2023-04-27 11:00  E6-2 #1322  Inverse Shapiro steps and coherent quantum phase slip in superconducting nanowires
455 2023-04-14 12:00  E6-2 #1323  (응집물리 세미나)Exotic quantum phenomena in two-dimensional materials file
454 2023-04-13 11:00  Zoom  [High Energy Theory Seminar]Noninvertible Gauss Law and Axions
453 2023-04-06 16:00  E6-2 #1323  (광학분야 세미나)Nanophotonics-based approaches to explore Berry physics
452 2023-04-05 16:00  E6-2, #2502  [High Energy Theory Seminar]Anomalies of Discrete 1-Form Symmetries in QCD-like Theories