Kim, Bogyu Jeon, Young-Uk Lee, Chulwoo Kim, In Soo Lee, Byeong-Hyeon Kim, Young-Hwan Kim, Young Duck Han, Il Ki Lee, Kwanil Kim, Jongbum Kang, JoonHyun 2024-01-19T12:31:39Z 2024-01-19T12:31:39Z 2022-04-21 2022-03 2045-2322 https://pubs.kist.re.kr/handle/201004/115540 In this study, we experimentally demonstrate fabrication of ultra-smooth and crystalline barium titanate (BTO) films on magnesium oxide (MgO) substrates by engineering lattice strain and crystal structure via thermal treatment. We observe that oxygen-depleted deposition allows growth of highly strained BTO films on MgO substrates with crack-free surface. In addition, post-thermal treatment relaxes strain, resulting in an enhancement of ferroelectricity. Surface roughening of the BTO films caused by recrystallization during post-thermal treatment is controlled by chemical-mechanical polishing (CMP) to retain their initial ultra-smooth surfaces. From Raman spectroscopy, reciprocal space map (RSM), and capacitance-voltage (C-V) curve measurements, we confirm that the ferroelectricity of BTO films strongly depend on the relaxation of lattice strain and the phase transition from a-axis to c-axis oriented crystal structure. English Nature Publishing Group Controlling of lattice strains for crack-free and strong ferroelectric barium titanate films by post-thermal treatment Article 10.1038/s41598-022-09182-0 1 Scientific Reports, v.12, no.1 Scientific Reports 12 1 Y scie scopus 000776283800046 Multidisciplinary Sciences Science & Technology - Other Topics Article SRTIO3 BUFFER LAYER THIN-FILM RAMAN-SPECTROSCOPY ENHANCEMENT