scholarly journals Ultra-high Critical Current Densities of Superconducting YBa2Cu3O7-d thin Films in the Overdoped State

2020 ◽  
Author(s):  
Alexander Stangl ◽  
Anna Palau ◽  
Guy Deutscher ◽  
Xavier Obradors ◽  
Teresa Puig
Keyword(s):  
Thin Films ◽  
Critical Current ◽  
Carrier Density ◽  
Quantum Critical Point ◽  
Coated Conductors ◽  
Hole Doping ◽  
Sudden Increase ◽  
Charge Carrier Density ◽  
Condensation Energy ◽  
A Value

Abstract Doping is one of the most relevant paths to tune the functionality of cuprates, it determines carrier density and the overall physical properties of these superconducting materials. We present an oxygen doping study of YBa2Cu3O7-d (YBCO) thin films from underdoped to overdoped state, correlating the measured charge carrier density, nH, the hole doping, p, and the critical current density, Jc. Our results show experimental demonstration of a linear correlation between Jc and nH, up to Quantum Critical Point (QCP), due to an increase of the superconducting condensation energy. The ultra-high Jc achieved, 90 MA cm-2 at 5 K corresponds to a third of the depairing current, i.e. a value 60 % higher than ever reported in YBCO films. The overdoped regime is confirmed by a sudden increase of nH, associated to the reconstruction of the Fermi-surface at the QCP. Overdoping YBCO opens a promising route to extend the current carrying capabilities of REBCO coated conductors for applications.

scholarly journals Ultra-high critical current densities of superconducting YBa2Cu3O7-δ thin films in the overdoped state

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Stangl ◽  
A. Palau ◽  
G. Deutscher ◽  
X. Obradors ◽  
T. Puig
Keyword(s):  
Thin Films ◽  
Critical Current ◽  
Carrier Density ◽  
Quantum Critical Point ◽  
Coated Conductors ◽  
Hole Doping ◽  
Strong Increase ◽  
Sudden Increase ◽  
Charge Carrier Density ◽  
Condensation Energy

AbstractThe functional properties of cuprates are strongly determined by the doping state and carrier density. We present an oxygen doping study of YBa2Cu3O7-δ (YBCO) thin films from underdoped to overdoped state, correlating the measured charge carrier density, $${n}_{\mathrm{H}}$$ n H , the hole doping, p, and the critical current density, $${J}_{c}$$ J c . Our results show experimental demonstration of strong increase of $${J}_{c}$$ J c with $${n}_{\mathrm{H}}$$ n H , up to Quantum Critical Point (QCP), due to an increase of the superconducting condensation energy. The ultra-high $${J}_{c}$$ J c achieved, 90 MA cm−2 at 5 K corresponds to about a fifth of the depairing current, i.e. a value among the highest ever reported in YBCO films. The overdoped regime is confirmed by a sudden increase of $${n}_{\mathrm{H}}$$ n H , associated to the reconstruction of the Fermi-surface at the QCP. Overdoping YBCO opens a promising route to extend the current carrying capabilities of rare-earth barium copper oxide (REBCO) coated conductors for applications.

Tuning of charge carrier density by deposition pressure in Sb-doped Bi2Se3 thin films

2020 ◽  
Vol 693 ◽  
pp. 137689
Author(s):  
S. Abhirami ◽  
Shilpam Sharma ◽  
E.P. Amaladass ◽  
R. Rajitha ◽  
P. Magudapathy ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Carrier ◽  
Carrier Density ◽  
Charge Carrier Density ◽  
Deposition Pressure

Relationship between critical current properties and nanorod morphology in REBa2Cu3Oy thin films

2012 ◽  
Vol 1434 ◽  
Author(s):  
M. Haruta ◽  
N. Fujita ◽  
Y. Ogura ◽  
T. Nakata ◽  
T. Maeda ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Fields ◽  
Critical Current ◽  
Growth Temperature ◽  
Coated Conductors ◽  
Laser Source ◽  
Bose Glass ◽  
Current Densities ◽  
Irreversibility Lines

ABSTRACTChanges in critical current properties depending on growth temperature (Ts) were clarified for Ba-Nb-O-doped YBa2Cu3Oy (Y123) films deposited by YAG- and excimer-PLD. Due to the introduction of Ba-Nb-O-nanorods, a vortex-Bose-glass-like behavior emerged as irreversibility lines and in-field critical current densities (Jcs) were improved. Crossover magnetic fields (Bcr) and in-field Jcs increased with the increase in Ts for the Y123 films with nanorods. These Ts-dependent critical current properties were attributable to the changes in morphology of the nanorods with Ts and were independent of laser source in PLD apparatuses. For the fabrication of RE123 coated conductors containing nanorods, optimization of Ts with taking both materials of RE123 matrix and nanorod into account is necessary to achieve higher in-field Jc.

Tc-δ Relations in YB2Cu3O7-δ Thin Films: Effects of Oxygen Pressure During Growth

1992 ◽  
Vol 275 ◽  
Author(s):  
R. Feenstra ◽  
D. P. Norton ◽  
J. D. Budai ◽  
D. K. Christen ◽  
D. H. Lowndes ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Carrier Density ◽  
Solid Phase ◽  
Hole Doping ◽  
Solid Phase Epitaxy ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxygen Capacity ◽  
Small Increments

ABSTRACTThe Tc dependence on oxygen content was measured for YBa2Cu3O7-δ films grown with a variety of techniques (solid phase epitaxy, laser ablation, off-axis sputtering, co-evaporation) at oxygen pressures p(O2) ranging from 1.0 atm to 0.1 mTorr. Dissimilar dependences resulted for each film type, with Tc either increasing or decreasing for small increments in δ from maximum oxygen occupancy. Varying systematically with p(O2) during growth, the deviations are attributed to competing effects from hole-doping lattice defects (most likely on the Y-site) on the carrier density of the CuO2 planes and basal plane oxygen capacity, respectively, giving rise to overdoping or underdoping after low temperature oxidation in 1.0 atm of oxygen.

scholarly journals Charge-carrier density collapse in and epitaxial thin films

2000 ◽  
Vol 14 (3) ◽  
pp. 509-513 ◽  
Author(s):  
W. Westerburg ◽  
F. Martin ◽  
P.J.M. van Bentum ◽  
J.A.A.J. Perenboom ◽  
G. Jakob
Keyword(s):  
Thin Films ◽  
Charge Carrier ◽  
Carrier Density ◽  
Epitaxial Thin Films ◽  
Charge Carrier Density

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Thermal Frequency Imaging: A New Application of Laser Voltage Imaging Applied on 40nm Technology

2011 ◽  
Author(s):  
Guillaume Celi ◽  
Sylvain Dudit ◽  
Thierry Parrassin ◽  
Philippe Perdu ◽  
Antoine Reverdy ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Laser Beam ◽  
Integrated Circuit ◽  
Carrier Density ◽  
Deep Submicron ◽  
Charge Carrier Density ◽  
Voltage Imaging ◽  
A New Technique ◽  
Scan Chain

Abstract For Very Deep submicron Technologies, techniques based on the analysis of reflected laser beam properties are widely used. The Laser Voltage Imaging (LVI) technique, introduced in 2009, allows mapping frequencies through the backside of integrated circuit. In this paper, we propose a new technique based on the LVI technique to debug a scan chain related issue. We describe the method to use LVI, usually dedicated to frequency mapping of digital active parts, in a way that enables localization of resistive leakage. Origin of this signal is investigated on a 40nm case study. This signal can be properly understood when two different effects, charge carrier density variations (LVI) and thermo reflectance effect (Thermal Frequency Imaging, TFI), are taken into account.

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