Heo Seungyang, Oh Chadol, Eom Man Jin, Kim Jun Sung, Ryu Jungho, Son Junwoo, Jang Hyun Myung
Division of Advanced Materials Science (AMS) and Department of Materials Science and Engineering (MSE), Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
Sci Rep. 2016 Feb 26;6:22228. doi: 10.1038/srep22228.
The band width control through external stress has been demonstrated as a useful knob to modulate metal-insulator transition (MIT) in RNiO3 as a prototype correlated materials. In particular, lattice mismatch strain using different substrates have been widely utilized to investigate the effect of strain on transition temperature so far but the results were inconsistent in the previous literatures. Here, we demonstrate dynamic modulation of MIT based on electric field-controlled pure strain in high-quality NdNiO3 (NNO) thin films utilizing converse-piezoelectric effect of (001)-cut Pb(Mg(1/3)Nb(2/3)O3-(PbTiO3) (PMN-PT) single crystal substrates. Despite the difficulty in the NNO growth on rough PMN-PT substrates, the structural quality of NNO thin films has been significantly improved by inserting SrTiO3 (STO) buffer layers. Interestingly, the MIT temperature in NNO is downward shifted by ~3.3 K in response of 0.25% in-plane compressive strain, which indicates less effective TMI modulation of field-induced strain than substrate-induced strain. This study provides not only scientific insights on band-width control of correlated materials using pure strain but also potentials for energy-efficient electronic devices.
通过外部应力进行带宽控制已被证明是调节作为典型关联材料的RNiO3中金属-绝缘体转变（MIT）的一个有用手段。特别是，到目前为止，使用不同衬底的晶格失配应变已被广泛用于研究应变对转变温度的影响，但先前文献中的结果并不一致。在此，我们利用（001）切割的Pb（Mg（1/3）Nb（2/3）O3-（PbTiO3）（PMN-PT）单晶衬底的逆压电效应，在高质量的NdNiO3（NNO）薄膜中展示了基于电场控制的纯应变对MIT的动态调制。尽管在粗糙的PMN-PT衬底上生长NNO存在困难，但通过插入SrTiO3（STO）缓冲层，NNO薄膜的结构质量得到了显著改善。有趣的是，在0.25%的面内压缩应变作用下，NNO中的MIT温度下降了约3.3K，这表明场致应变对TMI的调制效果不如衬底诱导应变。这项研究不仅为利用纯应变控制关联材料的带宽提供了科学见解，也为节能电子器件提供了潜力。
