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
192 Sep. 02(Fri) 2:30 PM  E6-2(1st fl.), #1323  Dr. Yong-Hyun Kim,Graduate School of Nanoscience and Technology, KAIST  Nanoscale Thermal Physics: Seebeck Effect and Nanoscale Friction
191 Sep. 02(Fri) 4:00 PM  E6-2(1st fl) #1323  Dr. Yong-Joo Doh, Department of Physics and Photon Science, GIST  Quantum Electrical Transport in Topological Insulator Nanowires
190 Jan. 17(Mon) - 21 (Fri), 2-4pm  E6-2 Room 2502  Dr. Donghui Jeong (Penn State University)  Five Lectures on Observational Probes of Dark Energy file
189 Nov. 12 (Thu.) 4:00 PM  E6-2 1323  김영덕 (Young Duck Kim) 교수  2020 가을학기 광학분야 특별세미나
188 Sep. 29th(Thu), 4PM  E6-2 #1323 (1st floor)  Dr. Sangyoon Han, Department of Physics, KAIST  Large-scale Silicon Photonic MEMS Switches
187 June 3(Fri.) 11:00  E6-2 #1323  Prof. Gil Young Cho (Department of Physics, POSTECH)  (응집물리 세미나) Theoretical Investigation of Exotic Quantum States in Low-dimensional Materials
186 Oct 23 (Fri.), 14:00 PM  E6-2 #1323  Prof. Ivan Savenko (University of Science and Technology & IBS PCS)  Plasmon spectroscopy of low-dimensional superconductors in fluctuating regime file
185 Oct. 10(Tue) 4PM  E6-2 #1323  김성웅 교수 (성균관대학교 에너지과학과)  Discovery of New 2D Materials with Diverse Physical Properties
184 DEC. 26 (Wed), 04:00 PM  E6-1. 3rd fl. #3434  Y. Kim, A. Go, K. Hwang and E.-G. Moon  Informal Workshop on Topology and Correlation file
183 October 24 (Wed.), 10:30 AM  E6-1, Lecture Room 1501(1F)  Prof. Kerry J. Vahala  Photonic integration of next-generation clocks and Hertz-absolute-accuarcy optical frequenncy synthesizers file
182 April 08(Fri.) 11:00  E6-1 #1323  Prof. Se-Young Jeong (Optics and Mechatronics Engineering , Pusan National University)  (응집물리 세미나) Flat-surface-assisted physical phenomena occurring in single crystal metal thin film file
181 Mar. 25(Fri.) 11:00  E6-1 #1323  Prof. Ara Go (Department of Physics, Chonnam National University)  (응집물리 세미나) Hund's metallicity in ruthenate systems file
180 May 20(Fri.) 11:00  E6-1 #1323  Prof. Kwanpyo Kim (Department of Physics, Yonsei University)  (응집물리 세미나) Exploration of new polymorphs in van der Waals crystals
179 2014/12/22, 2PM  E6, Rm1319  Prof. Changbong Hyeon (KIAS)  Dynamics of molecular motors: Power stroke vs Brownian ratchet file
178 2016/03/07-06/13  E6, 1501  Prof. David Helfman(KAIST) 외  Physics Colloquium : 2016 Spring file
177 2015/09/07-12/01  E6, 1501  문은국 교수(KAIST) 외  Physics Colloquium : 2015 Fall file
176 2015/03/09-06/08  E6, 1501  최현용교수(연세대) 외12명  Physics Colloquium : 2015 Spring file
175 2015/09/15-12/08  E6, 1501  박제근 교수(서울대 물리학과) 외12명  Physics Colloquium : 2014 Fall file
174 2014/03/10-06/09  E6, 1501  신용일교수(서울대)  Physics Colloquium : 2014 Spring file
173 2013/09/09-12/09  E6, 1501  박혁규교수(부산대) 외  Physics Colloquium : 2013 Fall