Superconductivity and valence states of Ce, Pr and Tb in bulk Lu1−xMxBa2Cu3O7−δ (M = Ce, Pr and Tb) systems

Gnanasekar, K. I. ; Tamhane, A. S. ; Pinto, R. ; Nagarajan, R. ; Sharon, M. ; Gupta, L. C. ; Vijayaraghavan, R. (1994) Superconductivity and valence states of Ce, Pr and Tb in bulk Lu1−xMxBa2Cu3O7−δ (M = Ce, Pr and Tb) systems Physica C: Superconductivity, 219 (1-2). pp. 183-190. ISSN 0921-4534

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/0...

Related URL: http://dx.doi.org/10.1016/0921-4534(94)90032-9

Abstract

Bulk samples of composition Lu1−xMxBa2Cu3O7−δ (M=Ce, Pr and Tb) are examined with respect to the formation of 1-2-3 phase and the superconducting properties. Samples with M = Pr and Tb form a superconducting 1-2-3 phase for values of x≤0.6. We observe that in case of M = Tb, the zero-resistance transition temperature, Tc(0), is 85-86 K and independent of x for 0.1 ≤x ≤0.3. For M = Pr, a maximum Tc(0) of 86 K is observed for x=0.1. Tc(0) decreases with increasing x for x > 0.1 and the sample with x=0.6 is observed to be semiconducting down to 12 K. With M = Ce, samples of the composition Lu1−x−yCexCayBa2Cu3 O7−δ form the superconducting 1-2-3 phase for x, Y=0.1 and 0.15. Samples of the compositions Lu1−x−yPrxCayBa2Cu3 O7−δ with x=0.1, 0.2, 0.3 and y=0.1, have lower Tc(0)'s than samples of a corresponding Pr content without Ca. We infer from our studies that the Pr ions are in the 3+ valence state for 0.1≤x≤0.3, the Tb ions are mainly in the 3+ valence state for 0.1≤x≤0.3, and the Ce ions are in the 4+ state.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:61833
Deposited On:15 Sep 2011 11:56
Last Modified:10 Jul 2012 08:33

Repository Staff Only: item control page