The specific heat of samples of Y1-xPrxBa2Cu3O7-y for x = 0.1 to 0.5 has been measured from 4.5 to 65 K using a quasi-adiabatic calorimeter. A plot of C/T vs T2 shows a linear behavior below 20 K. The excess specific heat due to praseodymium in all the compounds is obtained by subtracting the specific heat of YBa2Cu3O7-x from the that of doped compound. The excess specific heat shows a peak near 19 K and its height decreases with increase in x. The excess specific heat could be interpreted on the basis of Schottky anomalies due to Pr3+ and Pr4+ ions, the peak at 19 K arising from the former. The fraction of Pr3+ ion obtained from a fit to the specific heat curves decreases from 0.30 for x = 0.1 to 0.05 for x = 0.5. © 1988.

Sankaranarayanan V

Department Of Physics

Venkataraman Sankaranarayanan

L. S. Vaidhyanathan

G. Rangarajan

K. Antony Thomas

PRASEODYMIUM AND ALLOYS

Superconducting materials

Diamagnetic susceptibility

EXCESS SPECIFIC HEAT

SCHOTTKY ANOMALIES

Tetragonal structure

Transition temperature

Yttrium Barium Copper Oxide

Yttrium compounds

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IIT Madras

Specific heat of praseodymium doped yttrium barium copper oxide

Solid State Communications

The role of Al substitution in single crystals of PrBa2Cu3O7-δ (PBCO) has been investigated using low temperature magnetic susceptibility and heat capacity measurements. The crystal composition and the amount of impurity have been determined using electron probe microanalysis (EPMA) and the lattice parameters have been determined using X-ray diffraction. Heat capacity measurements on single crystals of PrBa2Cu3-yAlyO7-δ reveal a sharp peak at 16.6 K for y = 0.0 originating from an antiferromagnetic ordering of the Prion moments (TN) and broader transitions at ≈ 10 K for y = 0.25 and ≈ 5.3 K for y = 0.4. Subtle anomalies are also found at these temperatures in the magnetic susceptibilities. The present results along with the neutron diffraction studies demonstrate the deleterious role of Al on the magnetic properties in this sample. © 1998 Elsevier Science B.V. All rights reserved.

Physica C: Superconductivity and its Applications

Influence of Al substitution in PrBa2Cu3O7-δ single crystals

The crystal structure, and magnetic susceptibilities of single crystals of PrBa2Cu3O7-δ are reported here. The crystals are tetragonal with space group P4/mmm. A crystal field (CF) Hamiltonian appropriate to tetragonal symmetry at the Pr3+ site was diagonalised considering J-mixing. A set of CF parameters is being reported which fits the susceptibility data closely and explains the reported results of inelastic neutron scattering measurements also reasonably well. © 1993.

Structural and crystal field studies on a single crystal of PrBa2Cu3O7-δ

Critical current density measurements were performed on compounds of the type (PrxY1-x)Ba2Cu3O7-y as a function of temperature, applied magnetic field and composition. The analysis yielded results which are qualitatively similar to those observed in the case of YBa2(Cu1-xFex)3O2 and TI-2122 as well as 2223 compounds. © 1991.

Cryogenics

Intragrain critical current density of superconducting compounds of the type (PrxY1-x)Ba2Cu3O7-y

Magnetization was measured on Pr-doped YBa2Cu3O7−y for fields up to 5·5T. The paramagnetic behaviour is correlated to the free ion values of Pr3+ and Pr4+. Hysteresis experiments were done for superconducting composition for fields up to 1100 Gauss. The intragrain critical current density is calculated using Bena’s formula. © 1991, Indian Academy of Sciences. All rights reserved.

Fulltext

Bulletin of Materials Science

DC magnetization studies of (PrxY1−x)Ba2Cu3O7−y

Journal	Solid State Communications
ISSN	00381098
Open Access	No