Transport, magnetic, and 57Fe and 155Gd Mossbauer spectroscopic properties of GdFeAsO and the slightly overdoped superconductor Gd0.84Th0.16FeAsO

Authors

Pu Wang, University of Ottawa
Zbigniew M. Stadnik, University of Ottawa
Cao Wang, Zhejiang UniversityFollow
Guanghan Cao, Zhejiang University
Zhu-An Xu, Zhejiang University

RIS ID

69970

Publication Details

Wang Pu, Stadnik Zbigniew M, Wang Cao, Cao Guang-Hanand, Xu Zhu-An,. Transport, magnetic, and ⁵⁷Fe and ¹⁵⁵Gd Mossbauer spectroscopic properties of GdFeAsO and the slightly overdoped superconductor Gd_0.84Th_0.16FeAsO., Journal of Physics: Condensed Matter, V. 22, n. 14, pp.

Abstract

The results of x-ray diffraction, electrical resistivity, magnetic susceptibility, and ⁵⁷Fe and ¹⁵⁵Gd Mössbauer spectroscopy studies of polycrystalline samples of nonsuperconducting GdFeAsO and superconducting Gd_0.84Th_0.16FeAsO are reported. The superconductor Gd_0.84Th_0.16FeAsO has the onset transition temperature of 54.4(1) K. We find that Fe and Gd magnetic moments in GdFeAsO order antiferromagnetically at 132.7(1) K and 4.1(1) K, respectively. In Gd_0.84Th_0.16FeAsO, Fe atoms carry no magnetic moment down to 1.9 K whereas Gd magnetic moments order below 2.9(1) K. This is taken as evidence for the coexistence of Gd magnetic order and superconductivity. The Debye temperatures of GdFeAsO and Gd_0.84Th_0.16FeAsO are, respectively, 409(4) and 389(3) K.