Phase separation and microstructural evolution of the perovskite and pyrochlore structures in Pb-based multi-cation complex Oxides: A transmission electron microscopy study

• Published in: Applied surface science 2024-05, Vol.655, p.159566, Article 159566
• Main Authors: Hoon Kim, Jong, Jae Jeong, Yun, Tae Jang, Woo, Jung Kim, You, Shin, Il-Kyun, Soo Kim, Chung, Hye Lee, Ji, Ho Park, Bae, Cho, Jae-Hyeon, Jo, Wook, Heon Kim, Young
• Format: Article
• Language: English
• Subjects: Microstructural evolution; Pb-based complex oxide; Perovskite; Phase separation; Pyrochlore structure; Transmission electron microscopy
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.159566

[Display omitted] •Pb-based complex oxide film was grown on a SrRuO3/SrTiO3 substrate via PLD.•HRTEM, FFT, and HR HAADF STEM analyses were used to elucidate its atomic structure.•Results revealed a perovskite phase and a novel pyrochlore phase in film matrix.•Pb2(Nb0.56Zr0.77Ti0.67)O7 (pyrochlore) and Pb(Nb0.4Zr0.3Ti0.3)O3 (perovskite)•Multifunctional features and improved physical properties for complex oxide systems. Multi-cation perovskite thin films are attracting significant research attention, owing to their unique physical properties. In particular, studies that provide insight into the microstructural properties and growth mechanisms of multi-cation Pb-based complex oxide thin films are highly desirable. The microstructural properties of Pb-based complex oxide thin films were studied using various transmission electron microscopy (TEM) techniques. The pyrochlore structure was elucidated by studying the atomic structure using HR (high-resolution) TEM, fast Fourier transform, and HR high-angle annular dark-field scanning transmission electron analyses. Additionally, the chemical properties of the multi-cation sites were characterized by energy-dispersive X-ray spectrometry, whereby the chemical composition of the pyrochlore structure was identified as Pb2(Nb0.56Zr0.77Ti0.67)O7 and that of the perovskite structure as Pb(Nb0.4Zr0.3Ti0.3)O3. The specific orientation relationship, [110]Pyrochlore//[010]Perovskite and (2¯20)Pyrochlore//(100)Perovskite, was confirmed between the pyrochlore and perovskite structures at the bottom area of the layer. However, tilting of the pyrochlore-structured grains was frequently observed with increasing thickness. Finally, recovery of the interplanar spacings was observed in the perovskite and pyrochlore phases.