Abstract

FUJIWARA, N. et al. Nuclear magnetic resonance on LaFeAsO0.4H0.6 at 3.7 GPa. Pap. Phys. [online]. 2019, vol.11, n.1, pp.1-5. ISSN 1852-4249.  http://dx.doi.org/10.4279/PIP.110002.

A prototypical electrondoped iron-based superconductor LaFeAsOi-xHx undergoes an antiferromagnetic (AF) phase for x > 0.49. We have performed nuclear magnetic resonance (NMR) measurements on LaFeAsO0.4H0.6 at 3.7 GPa to investigate the magnetic properties in the vicinity of a pressure-induced quantum critical point (QCP). The linewidth of 2H-NMR spectra broadens at low temperatures below 30 K, suggesting that the spin moments remain ordered at 3.7 GPa. The coexistence of gapped and gapless spin excitations was confirmed in the ordered state from the relaxation time T1 of 75 As. The pressure-induced QCP is estimated to be 4.1 GPa from the pressure dependence of the gapped excitation.

Keywords : NMR, high pressure, iron pnictide, superconductor.

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