Robust charge stripe order under high electric fields in ${\mathrm{Nd}}_{1.67}{\mathrm{Sr}}_{0.33}\mathrm{Ni}{\mathrm{O}}_4$

The influence of high electric fields on the charge stripe order in ${\mathrm{Nd}}_{1.67}{\mathrm{Sr}}_{0.33}\mathrm{Ni}{\mathrm{O}}_4$ was studied by means of simultaneous hard x-ray diffraction and electrical transport experiments. Direct measurements of the charge stripe satellite peaks in zero and high electric fields provide no evidence for a deformation or a sliding of the stripe lattice, which contradicts previous indications from nonlinear conductance effects. By using the order parameter of a structural phase transition for instant sample temperature measurements, nonlinear transport effects can be attributed to resistive heating. Implications for the pinning of stripes in the nickelates are discussed.

Figure 1

(Color online) $T$ dependence of the in-plane resistivity $\rho$ ($▵$, $I=100\mathrm{nA}$, Keithley 2410; $▿$, Keithley 2000, $I$ varying), as well as the integrated intensity of the charge stripe peak $(0,4-2ϵ,3)$ and the superstructure peak (1,1,0).

Figure 2

Current dependence of (a) the applied in-plane field $E$ and (b) the (1,1,0) peak intensity for different $T_{\mathrm{CF}}$. The arrows in (a) mark the threshold field.

Figure 3

(Color online) In-plane current normalized to $E_0=0.4\mathrm{kV}∕\mathrm{cm}$, and the (1, 1, 0) peak intensity vs $T_{\mathrm{CF}}$ for different $E$ fields. (a),(b) Continuous $E$ field. (c),(d) Pulsed $E$ field $\left(200\mathrm{ms}\right)$. $I_{\text{limit}}$ is $1.2\mathrm{mA}$ ($0.6\mathrm{mA}$ for $0.4\mathrm{kV}$ up). $E$ values are valid for $I<I_{\text{limit}}$, only. As soon as $I=I_{\text{limit}}$, $E$ decreases with increasing $T_{\mathrm{CF}}$.

Figure 4

$k$ and $l$ scans through $(0,4-2ϵ,3)$ charge peak at zero and finite continuous current. The peak shift observed in the $k$ scans is due to the contraction of the $b$ axis in the LTLO phase.