Abnormal Transport and Magnetic Properties Induced by Change of the Phase Volume Ratio for YBa{sub 2}Cu{sub 3}O{sub 7-δ}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} Hybrids

Journal Article · Sun Jul 15 00:00:00 EDT 2018 · Journal of Superconductivity and Novel Magnetism

DOI:https://doi.org/10.1007/S10948-017-4470-1· OSTI ID:22773971

Chen, Changzhao; Zhang, Wuqiong; Zhu, Shiwang ^[1]; Cai, Chuanbing ^[2]

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1. Anhui University of Science and Technology, College of Mechanics and Optoelectronic Physics (China)
2. Shanghai University, Shanghai Key Laboratory of High Temperature Superconductors (China)

Two elaborately designed hybrids consisting of superconducting YBa{sub 2}Cu{sub 3}O{sub 7-δ} (YBCO) and ferromagnetic La{sub 0.67}Sr{sub 0.33}MnO{sub 3} (LSMO), namely 20 × (YBCO(m)/LSMO(100 − m)) are prepared on single crystal SrTiO{sub 3} (STO) by pulsed laser deposition (PLD) with 20 being repetition periods and m = 90 and 10, respectively, which represents YBCO pulse number in a period. The films show highly c-oriented and epitaxial quality, suggested by XRD 𝜃–2𝜃 scans and pole figures. The 20 × (YBCO90/LSMO10) sample with a large YBCO volume fraction exhibits the typical character of a metal superconductor at about 90 K, while its transition width reaches 9.1 K, which is nearly eight times of that of the pure YBCO film. Above the superconducting transition temperature, a superparamagnetic signal rather than ferromagnetic behavior is observed, which may be associated with a diluted system consisting of the ferromagnetic nanoparticles embedded in the superconducting films. For the hybrid with a small YBCO volume fraction, i.e., the 20 × (YBCO10/LSMO90) sample, its transport behavior at normal state is insulating, and it is found that the Mott variable range hopping conduction dominates in this insulating phase in the temperature range 70–310 K. Obviously distinguishable insulator to superconductor (IS) transition occurs at 52 K, but the superconducting diamagnetic signals are very weak in the magnetic measurements below the IS temperature. For this sample, the magnetization loop at 100 K is ferromagnetic, yet manifested by a reduced coercive field and residual magnetization as compared with a pure LSMO film. In fact, both hybrids represent two kinds of nanocomposites, i.e., superconducting nanoparticles in a ferromagnetic matrix and ferromagnetic nanoparticles in a superconducting matrix, which benefits to study interfacial interactions due to an increased interface to value ratio and reduced size effect.

• OSTI ID: 22773971
• Journal Information: Journal of Superconductivity and Novel Magnetism, Vol. 31, Issue 7; Other Information: Copyright (c) 2018 Springer Science+Business Media, LLC, part of Springer Nature; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA); ISSN 1557-1939
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
COPPER OXIDES
ENERGY BEAM DEPOSITION
EPITAXY
FERROMAGNETIC MATERIALS
HIGH-TC SUPERCONDUCTORS
LASER RADIATION
MAGNETIC PROPERTIES
MAGNETIZATION
MONOCRYSTALS
MOTT SCATTERING
NANOCOMPOSITES
NANOPARTICLES
PULSED IRRADIATION
PULSES
STRONTIUM TITANATES
SUPERCONDUCTING FILMS
SUPERPARAMAGNETISM
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
YTTRIUM OXIDES