TY - JOUR
T1 - Pyrolysis behaviors dominated by the reaction-diffusion mechanism in the fluorine-free metal-organic decomposition process
AU - Shi, Jiangtao
AU - Zhao, Yue
AU - Wu, Yue
AU - Chu, Jingyuan
AU - Tang, Xiao
AU - Li, Xiaohang
AU - Yu, Xin
AU - Wu, Wei
AU - Jiang, Guangyu
AU - Suo, Hongli
AU - Jin, Zhijian
N1 - KAUST Repository Item: Exported on 2021-01-14
Acknowledgements: The authors would like to acknowledge the financial support from the Shanghai Committee of Science and Technology, China (Grant No. 19511106900), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the Instrument Analysis Center of Shanghai JiaoTong University for PPMS measurements, the Center for Advanced Electronic Materials and Devices (AEMD) for SEM observation, and thanks eceshi (www.eceshi.cn) for the nanoindentation analysis.
PY - 2020
Y1 - 2020
N2 - Owing to the advantages of its environmentally friendly process and superior high growth rate, the fluorine-free metal-organic decomposition (FF-MOD) is a promising route for the growth of REBa2Cu3O7-δ (REBCO, where RE is Y or other rare-earth elements) superconducting films. In this work, the pyrolysis behaviors dominated by the reaction-diffusion mechanism were investigated. Combining the atomic force microscopy and the nanoindentation analysis, we concluded that the strain generated by decomposition reactions plays a crucial role in defect formation. Due to the smooth release of the strain and enhancement of the mechanical properties, the defect-free film could be obtained under a fast process. However, an inhomogeneous microstructure along the film thickness was always found by cross-section observation, i.e., a dense layer at the top, while a porous layer was found at the bottom, being separated by a clear boundary. Accordingly, the one-dimensional reaction-diffusion model is proposed. In addition, the formation of such laminar structure is associated with different reaction mechanisms, depending on the diffusion of oxygen and evolved gases. Moreover, severe copper segregation was discerned in the dense layer, which would heavily affect the superconducting phase transformation. Remarkably, a high critical current density value exceeding 2 MA cm-2 (77 K, self-field) was achieved in the GdBa2Cu3O7 films grown on the CeO2 buffered technical substrates. This work provides deep insight into the pyrolysis behaviors of the FF-MOD route in view of the fabrication of REBCO superconducting films with high throughput. This journal is
AB - Owing to the advantages of its environmentally friendly process and superior high growth rate, the fluorine-free metal-organic decomposition (FF-MOD) is a promising route for the growth of REBa2Cu3O7-δ (REBCO, where RE is Y or other rare-earth elements) superconducting films. In this work, the pyrolysis behaviors dominated by the reaction-diffusion mechanism were investigated. Combining the atomic force microscopy and the nanoindentation analysis, we concluded that the strain generated by decomposition reactions plays a crucial role in defect formation. Due to the smooth release of the strain and enhancement of the mechanical properties, the defect-free film could be obtained under a fast process. However, an inhomogeneous microstructure along the film thickness was always found by cross-section observation, i.e., a dense layer at the top, while a porous layer was found at the bottom, being separated by a clear boundary. Accordingly, the one-dimensional reaction-diffusion model is proposed. In addition, the formation of such laminar structure is associated with different reaction mechanisms, depending on the diffusion of oxygen and evolved gases. Moreover, severe copper segregation was discerned in the dense layer, which would heavily affect the superconducting phase transformation. Remarkably, a high critical current density value exceeding 2 MA cm-2 (77 K, self-field) was achieved in the GdBa2Cu3O7 films grown on the CeO2 buffered technical substrates. This work provides deep insight into the pyrolysis behaviors of the FF-MOD route in view of the fabrication of REBCO superconducting films with high throughput. This journal is
UR - http://hdl.handle.net/10754/666893
UR - http://xlink.rsc.org/?DOI=D0TC03851B
UR - http://www.scopus.com/inward/record.url?scp=85098585525&partnerID=8YFLogxK
U2 - 10.1039/d0tc03851b
DO - 10.1039/d0tc03851b
M3 - Article
SN - 2050-7526
VL - 8
SP - 17417
EP - 17428
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
IS - 48
ER -