Local metallic and structural properties of the strongly correlated metal LaNiO3 using 8Li β–NMR

Abstract

We report β-detected NMR of ion-implanted 8 Li in a single crystal and thin film of the strongly correlated metal LaNiO 3 . In both samples, spin-lattice relaxation measurements reveal two distinct local metallic environments, as is evident from T-linear Korringa 1/T 1 below 200 K with slopes comparable to other metals. A small, approximately temperature independent Knight shift of ∼74 ppm is observed, yielding a normalized Korringa product characteristic of substantial antiferromagnetic correlations, but, we find no evidence for a magnetic transition from 4 to 310 K. Two distinct, equally abundant 8 Li sites is inconsistent with the widely accepted rhombohedral structure of LaNiO 3 , but cannot be simply explained by either of the common alternative orthorhombic or monoclinic distortions. arXiv:1906.07878v1 [cond-mat.str-el]

Evolution of the metallic state of LaNiO$_3$/LaAlO$_3$ superlattices measured by $^8$Li $β$-detected NMR

“…Biexponential relaxation appears intrinsic to 8 Li in LaNiO 3 , and a similar analysis was necessary for a bulk single crystal. 7 Interestingly, the fast relaxing fraction 𝑓 𝑓 = 50 % independent of LaNiO 3 thickness, and in agreement with the bulk. 7 For further details on the analysis, see the Supporting Information.…”

“…7 Interestingly, the fast relaxing fraction 𝑓 𝑓 = 50 % independent of LaNiO 3 thickness, and in agreement with the bulk. 7 For further details on the analysis, see the Supporting Information.…”

“…The slow rate in panel (a) remains linear (metallic) for all the SLs, with a slope similar to bulk LaNiO 3 . 7 Closer inspection reveals that: 1) above ∼200 K (marked by the vertical arrow), 1/𝑇 1 becomes sublinear; 2) the SLs are all faster relaxing than the bulk, and this enhancement is mostly due to a finite 𝑛-independent intercept as 𝑇 → 0; and 3) the slope changes systematically with 𝑛, but not monotonically, as the shallowest slope is at 𝑛 = 4. Below 200 K, we fit (1/𝑇 1 ) 𝑠 to a line to obtain the values shown as a function of 𝑛 in Figure 3.…”

“…𝛽-NMR is a powerful tool for studying metals, 5 including strongly correlated Sr 2 RuO 4 6 and LaNiO 3 . 7 Here, 𝛽-NMR is used to study the evolution of the metallic state of LaNiO 3 with decreasing thickness in a series of LaNiO 3 /LaAlO 3 SLs. Spin-lattice relaxation (SLR) measurements reveal two components: one with 𝑇-linear relaxation below 200 K, and a second with a more complex 𝑇-dependence.…”

Probing Electronic and Magnetic Transitions of Short Periodic Nickelate Superlattices Using Synchrotron X-rays

“…Further, Mandal et al have demonstrated that the BD phase appears when the effective charge transfer energy becomes negative [42]. Surprisingly, signatures of breathing distortion have been also found in the metallic phase of LaNiO3 [43]. On the other hand, there are also reports emphasizing the importance of structural transition [44,45] and polaron condensation [46].…”