Specific heat of praseodymium doped yttrium barium copper oxide

• Published in: Solid state communications 1988-07, Vol.67 (4), p.391-395
• Main Authors: Sankar, N., Sankaranarayanan, V., Vaidhyanathan, L.S., Rangarajan, G., Srinivasan, R., Thomas, K.A., Varadaraju, U.V., Subba Rao, G.V.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Physics; Properties of type I and type II superconductors; Superconductivity
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/0038-1098(88)91051-4

The specific heat of samples of Y 1−xPr xBa 2Cu 3O 7−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 T 2 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 YBa 2Cu 3O 7−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 Pr 3+ and Pr 4+ ions, the peak at 19 K arising from the former. The fraction of Pr 3+ 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.