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Comparing the physical properties of Pr/Gd and Pr/Ce substitutions in Ru(Gd 1.5Ce 0.5)Sr 2Cu 2O 10-δ

Khajehnezhad, A ; Sharif University of Technology | 2008

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  1. Type of Document: Article
  2. DOI: 10.1140/epjb/e2008-00257-y
  3. Publisher: 2008
  4. Abstract:
  5. We have compared the electrical and magnetic properties of Ru(Gd 1.5-x Pr x )Ce 0.5Sr 2Cu 2O 10-δ (Pr/Gd samples) with x = 0.0, 0.01, 0.03, 0.033, 0.035, 0.04, 0.05, 0.06, 0.1 and RuGd 1.5(Ce 0.5-x Pr x ) Sr 2 Cu 2O 10-δ (Pr/Ce samples) with x = 0.0, 0.01, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2 prepared by the standard solid-state reaction technique. We obtained the XRD patterns for different samples with various x. The lattice parameters versus x for different substitutions have been obtained from Rietveld analysis. To determine how the magnetic and superconducting properties of these layered cuprate systems can be affected by Pr substitution, the resistivity, and magnetoresistivity, with H ext varying from 0.0 to 15 kOe, have been measured at various temperatures. Superconducting transition temperature T c and magnetic transition T irr , have been obtained through resistivity and ac susceptibility measurements. The T c suppression due to Pr/Gd and Pr/Ce substitutions show competition between pair breaking by magnetic impurities, hole doping due to different valances of ions, difference in ionic radii, and oxygen stoichiometry. Pr/Gd substitution suppresses superconductivity more rapidly than for Pr/Ce, showing that the effect of hole doping and magnetic impurity pair breaking is stronger than the difference in ionic radii. In Pr/Gd substitution, the small difference between the ionic radii of Pr 3+,4+ and Gd 3+, and absorption of more oxygen due to the higher valence of Pr with respect to Gd, decreases the mean Ru-Ru distance, and as a result, the magnetic exchange interaction becomes stronger with the increase of x. However, Pr/Ce substitution has the opposite effect. The magnetic parameters such as H c , obtained through magnetization measurements versus applied magnetic field isotherm at 77 K and room temperatures, become stronger with x in Pr/Gd and weaker with x in Pr/Ce substitution. © 2008 Springer-Verlag
  6. Keywords:
  7. Electrical and magnetic properties ; Physical Properties ; Magnetic properties ; Gadolinium
  8. Source: European Physical Journal B ; Volume 63, Issue 4 , 2008 , Pages 461-467 ; 14346028 (ISSN)
  9. URL: https://link.springer.com/article/10.1140%2Fepjb%2Fe2008-00257-y