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arXiv · 1808.05153

c-axis pressure induced antiferromagnetic order in optimally P-doped BaFe2(As0.70P0.30)2 superconductor

Ding Hu·Weiyi Wang·Wenliang Zhang·Yuan Wei·Dongliang Gong·David W. Tam·Panpan Zhou·Yu Li·Guotai Tan·Yu Song·Robert Georgii·Bjorn Pedersen·Huibo Cao·Wei Tian·Bertrand Roessli·Zhiping Yin·Pengcheng Dai
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Abstract

Superconductivity in BaFe2(As1-xPx)2 iron pnictides emerges when its in-plane two-dimensional (2D) orthorhombic lattice distortion associated with nematic phase at Ts and three-dimensional (3D) collinear antiferromagnetic (AF) order at TN (Ts = TN) are gradually suppressed with increasing x, reaching optimal superconductivity around x = 0.30 with Tc $\approx$ 30 K. Here we show that a moderate uniaxial pressure along the c-axis in BaFe2(As0.70P0.30)2 spontaneously induces a 3D collinear AF order with TN = Ts > 30 K, while only slightly suppresses Tc. Although a ~ 400 MPa pressure compresses the c-axis lattice while expanding the in-plane lattice and increasing the nearest-neighbor Fe-Fe distance, it barely changes the average iron-pnictogen height in BaFe2(As0.70P0.30)2. Therefore, the pressure- induced AF order must arise from a strong in-plane magnetoelastic coupling, suggesting that the 2D nematic phase is a competing state with superconductivity.

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Ding Hu, Weiyi Wang, Wenliang Zhang, Yuan Wei, Dongliang Gong, David W. Tam, Panpan Zhou, Yu Li, Guotai Tan, Yu Song, Robert Georgii, Bjorn Pedersen, Huibo Cao, Wei Tian, Bertrand Roessli, Zhiping Yin, Pengcheng Dai. 2018-08-15. c-axis pressure induced antiferromagnetic order in optimally P-doped BaFe2(As0.70P0.30)2 superconductor. https://doi.org/10.1038/s41535-018-0122-3

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