Effect and Mechanism of Doping Concentration on Growth and Performance of Thick BaHfO3-doped Y0.5Gd0.5Ba2Cu3O7−δ Films by Pulsed Laser Deposition

• Published in: Journal of superconductivity and novel magnetism Vol. 35; no. 2; pp. 435 - 444
• Main Authors: Ye, Jiachao, Mou, Shaojing, Zhu, Rongji, Liu, Linfei, Li, Yijie
• Format: Journal Article
• Language: English
• Published: New York Springer US 2022
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Magnetic Materials; Magnetism; Original Paper; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconductivity; films; Strain field; Cu; Pulsed laser deposition; Diffusion energy; BaHfO; Gd; doped Y; Ba; O
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-021-06078-4

One mole percent and 3 mol% BaHfO 3 -doped Y 0.5 Gd 0.5 Ba 2 Cu 3 O 7− δ films with thickness of micron level were prepared on CeO 2 layer under different laser fluences respectively by pulsed laser deposition. Under a higher laser fluence, compared with 1 mol% BaHfO 3 -doped Y 0.5 Gd 0.5 Ba 2 Cu 3 O 7− δ film, 3 mol% BaHfO 3 -doped Y 0.5 Gd 0.5 Ba 2 Cu 3 O 7− δ film has lower self-field critical current density at 77 K, falling from 2.143 to 1.75 MA/cm 2 , although its surface is smoother. Under a lower laser fluence, both the thick films have poorer superconductivity and surface morphology, which has been explained by the appearance of a -axis-oriented grains and disordered particles on the surface caused by reduced diffusion energy. What is more, the superconductivity decays more as the BaHfO 3 doping concentration increases. The strain field due to lattice mismatch will further reduce the diffusion energy of Y 0.5 Gd 0.5 Ba 2 Cu 3 O 7− δ atoms, which will make it easier to form a -axis-oriented grain and degrade the film surface quality, thus aggravating the decrease of superconducting current.