Pal, Anand and Vajpayee, Arpita and Awana, V. P. S. and Husain, M. and Kishan, H. (2009) Suppression of spin density wave character of (Sm/Gd)FeAsO by substitution of Ru at Fe site. Physica C: Superconductivity, 470 (1). S491-S492. ISSN 0921-4534

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Abstract

We report synthesis, structural details and transport measurements on SmFe0.5Ru0.5AsO and GdFe0.5Ru0.5AsO. The samples are synthesized at normal pressure with vacuum encapsulation technique. The parent REFeAsO (RE = Sm and Gd) crystallizes in tetragonal P4/nmm space group having their lattice parameters as a = 3.9375(6) Å, c = 8.5021(4) Å for Sm and a = 3.9152(4) Å, c = 8.4546(1) Å for Gd. With 50% Ru substitution at Fe site i.e. for SmFe0.5Ru0.5AsO and GdFe0.5Ru0.5AsO the lattice parameter a is increased and c is decreased to as a = 4.0113(55) Å, c = 8.3129(17) Å for Sm and a = 3.9795(64) Å, c = 8.2787 (20) Å for Gd samples. Resistivity measurements on pristine samples though exhibited clearly the step like metallic transition at around 150 K, the Fe site 50% Ru substituted samples show all through a metallic behavior without the characteristic spin density wave (SDW) step. The samples with lower content of Ru at Fe site i.e. 10% and 30% are also studied. Though 10% Ru doped samples exhibited weak superconductivity like transition below 15 K, the 30% doped samples are metallic. It seems that the Fe2+ site Ru4+/5+ substitution provides electron carriers for conduction process. For achieving bulk superconductivity in Fe-site Ru substituted REFeAsO (1111) systems the efforts are still underway.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier B.V.
Subjects:	Physics
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	13 Jul 2012 13:03
Last Modified:	13 Jul 2012 13:03
URI:	http://npl.csircentral.net/id/eprint/342

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