Oxyanion derivatives of cuprate superconductors superconducting 123 phosphates

Nagarajan, R and Ayyappan, S and Rao, CNR (1994) Oxyanion derivatives of cuprate superconductors superconducting 123 phosphates. In: Physica C, 220 (3-4). pp. 373-376.

PDF Oxyanion-306.pdf Restricted to Registered users only Download (233kB) | Request a copy

Abstract

While $YSr_2Cu_30_7$ cannot be prepared under ambient conditions, partial substitution of the phosphate group for copper, as in $YSr_2Cu_{2.8}$ $(PO_4)_{o.2}0_{y'}$ stabilizes this phase in the orthorhombic structure, hut the material is not superconducting. Superconductivity in $YSr_2Cu_{2.8}(PO_4)_{0.2}O_y$ is obtained by increasing the hole concentration through partial substitution of Y by Ca, as in $Y_{0.7}Ca_{0.3}Sr_2Cu_{2.8}(PO_4)_{0.2}O_y ( T_c\approx47 K)$. By incorporating the phosphate group in orthorhombic $YBaSrCu_3O_7$, a stable tetragonat derivative of the formula $YBaSrCu_{2.8} (PO_4)_{0.2}O_y ( T_c\approx47 K)$ has been prepared; the $T_c$ increases to ~ 70 K by partial substitution of Y by Ca as in $Y_{0.7}Ca_{0.3}BaSrCu_{2.8} ( PO_4 )_{0.2}0_{y'}$

Item Type:	Journal Article
Publication:	Physica C
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	17 Oct 2006
Last Modified:	19 Sep 2010 04:30
URI:	http://eprints.iisc.ac.in/id/eprint/8246

Actions (login required)

View Item