Pulsed laser ablation-deposition of La_0.5Sr_0.5CoO_3 for use as electrodes in nonvolatile ferroelectric memories
Pulsed laser ablation-deposition of La_0.5Sr_0.5CoO_3 for use as electrodes in nonvolatile ferroelectric memories
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脉冲激光烧蚀沉积La_0.5Sr_0.5CoO_3，用作非易失性铁电存储器的电极
DOI：
10.1557/jmr.1996.0189
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
A. Kingon
中科院分区：
文献类型：
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作者：
R. Dat;O. Auciello;D. Lichtenwalner;A. Kingon
采用脉冲激光烧蚀沉积法（PLAD）在（100）MgO衬底上制备了La0.5Sr0.5CoO3（LSCO）薄膜。发现LSCO的晶体学取向依赖于沉积前（100）MgO的表面处理。优化PLAD沉积参数以产生RMS表面粗糙度为40-50 μ m的LSCO膜。只要保持LSCO靶的氧含量，就可以再现光滑的表面形态。否则，发生“飞溅”，这导致来自LSCO的熔融球形小球的冷凝颗粒从靶转移到衬底。在550 °C氧气中退火3 h后，随后消除了飞溅，并恢复了光滑的表面质量。LSCO羽流的光学发射光谱（OES）确定了激发的原子钴中性，激发的单离子化锶和镧，以及激发的分子LaO物种。氧气与羽流的相互作用没有产生新的物种。OES数据还表明，所观察到的LaO分子不是在烧蚀过程中由La和O_2之间的化学反应产生的，而是在PLAD过程中直接从靶中喷出的。
La_0.5Sr_0.5CoO_3 (LSCO) thin films have been deposited on (100) MgO substrates using pulsed laser ablation-deposition (PLAD). The crystallographic orientation of LSCO was found to be dependent on the surface treatment of (100) MgO prior to deposition. PLAD deposition parameters were optimized to yield LSCO films with an RMS surface roughness of 40–50 Å. A smooth surface morphology was reproduced as long as the oxygen content of the LSCO target was preserved. Otherwise, “splashing” occurred which resulted in the transfer of condensed particles from molten spherical globules of LSCO from the target to the substrate. Splashing was subsequently eliminated and smooth surface quality was restored after annealing the LSCO target at 550 °C in oxygen for 3 h. Optical emission spectroscopy (OES) of the LSCO’s plume identified excited atomic cobalt neutrals, excited singly ionized strontium and lanthanum, and excited molecular LaO species. Oxygen interaction with the plume produced no new species. Furthermore, the OES data suggest that the observed LaO molecules were not created by the chemical reaction between La and O_2 during ablation, but were ejected directly from the target during the PLAD process.