Studying manganite superlattices ${\left[{\left(\mathrm{LCMO}\right)}_{2n}/{\left(\mathrm{PCMO}\right)}_n\right]}_t$ made of ${\mathrm{La}}_{0.625}{\mathrm{Ca}}_{0.375}\mathrm{Mn}{\mathrm{O}}_3$ (LCMO) and ${\mathrm{Pr}}_{0.625}{\mathrm{Ca}}_{0.375}\mathrm{Mn}{\mathrm{O}}_3$ (PCMO), we found an unexpected behavior varying the period $n$. At small $n$, the ensemble is a three-dimensional ferromagnetic metal due to interfacial charge transfer. At large $n$, the LCMO layers dominate transport. However, rather than a smooth interpolation between these limits a sharp transport and magnetic anomaly is found at an intermediate critical PCMO thickness $n^{*}$. Magnetic force microscopy reveals that the phase-separation length scale also maximizes at $n^{*}$ where, unexpectedly, it becomes comparable to that of the ${\left({\mathrm{La}}_{1–y}{\mathrm{Pr}}_y\right)}_{0.625}{\mathrm{Ca}}_{0.375}\mathrm{Mn}{\mathrm{O}}_3$ (LPCMO) alloy. We conjecture the phenomenon originates in a disorder-related length scale: Large charge-ordered clusters as in LPCMO can only nucleate when Pr-rich regions reach a critical size related to $n^{*}$.

中文翻译：

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超晶格周期驱动的电子相分离锰超晶格的非单调穿越

研究锰超晶格 ${\left[{（\mathrm{劳工组织}）}_{2ñ}/{（\mathrm{PCMO}）}_{ñ}\right]}_{Ť}$ 由...制成 ${啦}_{0.625}{钙}_{0.375}锰{\mathrm{Ø}}_3$ （LCMO）和 ${镨}_{0.625}{钙}_{0.375}锰{\mathrm{Ø}}_3$ （PCMO），我们发现了不同时期的意外行为 $ñ$。在小$ñ$，由于界面电荷转移，该集合是三维铁磁金属。大体上$ñ$，LCMO层主导着运输。但是，不是在这些限制之间进行平滑插值，而是在中间临界PCMO厚度处发现了尖锐的传输和磁异常。${ñ}^{*}$。磁力显微镜显示相分离长度标度在${ñ}^{*}$ 出乎意料的是，它变得与 ${（{啦}_{\mathrm{1个}–ÿ}{镨}_{ÿ}）}_{0.625}{钙}_{0.375}锰{\mathrm{Ø}}_3$（LPCMO）合金。我们推测，这种现象起源于与疾病有关的长度尺度：LPCMO中的大型带电荷簇只能在富Pr区域达到与${ñ}^{*}$。