The properties of the Y1−xPrxBa2Cu3O7 (YPrBCO) system are reviewed. These include superconducting, normal state, structural, chemical, optical, magnetic, and thermal properties. The destruction of superconductivity with Pr doping is discussed in view of possible models such as hole filling, localization, magnetic pair-breaking, and the role of hybridization. Applications to electronic devices using YBCO/PrBCO/YBCO multilayers are also reviewed.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0884291400017489

A review of the superconducting and normal state properties of Y1−xPrxBa2Cu3O7

A variety of synthetic strategies has been employed to prepare pure monophasic cuprates of different families with good superconducting properties. Besides the traditional ceramic method, other methods such as coprecipitation and precursor methods, the sol-gel method, the alkali flux method and the combustion method have been employed for the synthesis of cuprates. Depending on the requirements, varying conditions such as high oxygen or hydrostatic pressure and low oxygen fugacity are employed in the synthesis. In this review, the authors discuss the synthesis of the various types of cuprate superconductors and point out the advantages and disadvantages of the different methods.

https://iopscience.iop.org/article/10.1088/0953-2048/6/1/001/pdf

Synthesis of cuprate superconductors

High-quality single crystals of R 2- x Ce x CuO 4- y (R = Nd, Sm) were prepared over a range of Ce dopings x using CuO flux. By optimizing the growth conditions, free standing platelet single crystals as large as 10x10x0.1 mm 3 were obtained reproducibly. TEM and SEM analyses verified that the crystals were single-phase with uniform Ce distribution. Both resistivity and magnetization showed sharp superconducting transitions (Δ T x =0.15. Because of the improved quality, the crystals are suitable for a definitive study of intrinsic properties. Details of the methods, post-growth annealing, and characterization of the crystals will be described.

Growth and characterization of high-quality single crystals of r2-xcexcuo4-y (r = nd, sm)

The phase diagrams for the binary and ternary Nd 2 O 3 -CuO and (0.85Nd 2 O 3 -0.3CeO 2 )- CuO systems are reported and the eutectic points and the liquid lines are determined. We have also explored the crystal growth from molten solutions of compositions 70% CuO-(30- z )% Nd 2 O 3 - z % CeO 2 for a range of CeO 2 concentrations. We show that the composition of the crystals is not uniform for a given z value but the compositional range appears to be quite narrow ( x =0.17(3)) for z =3.6. This concentration produces also the largest crystals (≈10 X 10 X 0.3 mm 3 ).

Crystal growth and phase diagrams for the Nd2O3-CeO2-CuO system

An experimental study of superconducting and non-superconducting Nd1.85Ce0.15CuO4+y, including structure determination by neutron powder diffraction, recording of oxygen changes by gas volumetry, and susceptibility and thermoelectric measurements, is reported. Difference neutron diffraction patterns from samples prepared on-line at the spectrometer show that the structures of superconducting and non-superconducting samples are identical within the limits set by the statistical errors of our data. Simultaneous gas volumetric measurements reveal that Δy

Crystal structure, magnetic susceptibility and thermopower of superconducting and non-superconducting Nd1.85Ce0.15CuO4+y

Compositional properties and thermoelectric power of the superconducting ceramic. Nd2−xCexCuO4−y

We report the development of a reaction technique which yields ceramic Nd 1.85 Ce 0.15 CuO 4−y with macroscopically uniform concentrations of Ce and O. Under appropriate argon annealing conditions, samples exhibiting bulk superconductivity as gauged by resistive transition width and diamagnetic shielding are obtained. In addition. metallic behavior, indicated by positive dp/dT above T c , is obtained for the normal state.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0884291400011675

The preparation and processing of bulk superconducting ceramic Nd 1.85 Ce 0.15 CuO 4 - y

PrBa 2 Cu 3 O 7−y is probably the most enigmatic member of the 1-2-3 family of compounds. It is the only non-superconducting example in this lanthanide series of isomorphic structures. We have studied its structural details, and dependence of its physical properties on oxygen concentration and solid solutions with Y, Ca and Zn, with the objective of understanding its peculiar behavior and the role Pr plays in suppressing superconductivity.

M.E. López-Morales

Papers

Compositional properties and thermoelectric power of the superconducting ceramic. Nd2−xCexCuO4−y

The preparation and processing of bulk superconducting ceramic Nd 1.85 Ce 0.15 CuO 4 - y

Praseodymium 1-2-3: Intrinsic structure, oxygen concentration effects, and solid solutions with yttrium, calcium and zinc