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arXiv · 1903.11706

Charge-stripe order, antiferromagnetism, and spin dynamics in the cuprate-analog nickelate La$_4$Ni$_3$O$_8$

Oscar O. Bernal·Douglas E. MacLaughlin·Gerald D. Morris·Pei-Chun Ho·Lei Shu·Cheng Tan·Jian Zhang·Zhaofeng Ding·Kevin Huang·Viktor V. Poltavets
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Abstract

We report a muon spin rotation ($μ$SR) study of the cuprate-analog nickelate La$_4$Ni$_3$O$_8$, which undergoes a transition at 105 K to a low-temperature phase with charge-stripe and antiferromagnetic (AFM) order on square planar NiO$_2$ layers. Zero-field $μ$SR shows that this transition is abrupt and that the AFM configuration is commensurate. Comparison of observed muon precession frequencies with Ni dipolar field calculations yields Ni moments $\lesssim 0.5μ_B$. Dynamic muon spin relaxation above 105 K suggests critical slowing of Ni spin fluctuations, but is inconsistent with corresponding $^{139}$La NMR results. Critical slowing and an abrupt transition are also observed in the planar cuprate AFM La$_2$CuO$_{4+δ}$, where they are evidence for weakly interplanar-coupled two-dimensional AFM spin fluctuations, but our $μ$SR data do not agree quantitatively with theoretical predictions for this scenario.

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Oscar O. Bernal, Douglas E. MacLaughlin, Gerald D. Morris, Pei-Chun Ho, Lei Shu, Cheng Tan, Jian Zhang, Zhaofeng Ding, Kevin Huang, Viktor V. Poltavets. 2019-07-30. Charge-stripe order, antiferromagnetism, and spin dynamics in the cuprate-analog nickelate La$_4$Ni$_3$O$_8$. https://doi.org/10.1103/physrevb.100.125142

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