[17p-A408-1~14] 6.3 Oxide electronics

[17p-A408-9] Laser-induced ultrafast phase transition of λ-Ti₃O₅ thin films

〇Ryunosuke Takahashi¹, Minato Yamasaki¹, Suguru Nakata¹, Kohei Yoshimatsu², Hiroshi Kumigashira², Hiroki Wadati^1,3 (1.Univ. of Hyogo, 2.Tohoku Univ., 3.Osaka Univ.)

Keywords:Phase transition, Oxide, Thin film

Ti₃O₅ has various states such as α-, β-, γ-, and δ-phases. In addition to these, a new metastable phase, the λ phase, has recently been discovered [1]. This phase is attractive for its ability to undergo various phase transitions upon external stimuli reflecting its metastable property. In particular, a photo-induced phase transition to the β-phase by nanosecond visible pulsed laser pulses and a pressure-induced phase transition was observed [1]. Time-resolved reflectance on bulk Ti₃O₅ was observed [2]. In this study, we have observed the time evolution of the transmittance and reflectance of λ-Ti₃O₅ thin films deposited at very high temperatures on LaAlO₃ (110) substrate [3] using a pump (1030 nm) - probe (1030 nm) method. The reflectance decreased and transmittance increased at the same time after the laser irradiation. In the presentation, we would like to discuss polarization dependence in addition to these ultrafast changes.
[1] S.-I. Ohkoshi et al., Nat. Chem. 2, 539−545 (2010).
[2] T. Saiki et al., Phys. Rev. B 105, 075134 (2022).
[3] K. Yoshimatsu et al., Cryst. Growth Des. 22, 703-710 (2022).