Synthesis of SmFeAsO by an easy and versatile route and its physical property characterization

Authors

V P. Awana, National Physical Laboratory, New Delhi
Anand Pal, National Physical Laboratory, New Delhi
Arpita Vajpayee, Natl Phys Lab, New Delhi 110012, India
H Kishan, Natl Phys Lab, New Delhi 110012, India
Gustavo A. AlvarezFollow
K Yamaura, National Institute Materials Science Japan
E Takayama-Muromachi, National Institute for Material Science (NIMS)

RIS ID

32215

Publication Details

Awana, V. P., Pal, A., Vajpayee, A., Kishan, H., Alvarez, G. A., Yamaura, K. Takayama-Muromachi, E. (2009). Synthesis of SmFeAsO by an easy and versatile route and its physical property characterization. Journal of Applied Physics, 107, 07E316-1-07E316-3.

Abstract

We report synthesis, structure, electrical transport, and heat capacity of SmFeAsO. The title compound is synthesized by one-step encapsulation of stoichiometric FeAs, Sm, and Sm₂O₃ in an evacuated (10⁻⁵ Torr) quartz tube by prolong (72 h) annealing at 1100 °C. The as-synthesized compound is crystallized in tetragonal structure with P4/nmm space group having lattice parameters a = 3.937 26(33) A and c = 8.498 02(07) A. The resistance (R-T) measurements on the compound exhibited ground state spin-density-wave (SDW)-like metallic steps below 140 K. Heat capacity C_P(T) measurements on the title compound, showed an anomaly at around 140 K, which is reminiscent of the SDW ordering of the compound. At lower temperatures the C_P(T) shows a clear peak at around 4.5 K. At lower temperature below 20 K, C_p(T) is also measured under an applied field of 7 T. It is concluded that the C_P(T) peak at 4.5 K is due to the antiferromagnetic ordering of Sm³⁺ spins. These results are in confirmation with ordering of Sm in Sm_2−xCe_xCuO₄.