Ferroelectric Domain Wall Engineering Enables Thermal Modulation in PMN–PT Single Crystals
Ferroelectric Domain Wall Engineering Enables Thermal Modulation in PMN–PT Single Crystals
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铁电畴壁工程实现 PMN–PT 单晶的热调制
DOI：
10.1002/adma.202211286
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发表时间：
2023
影响因子：
29.4
通讯作者：
Liu, Jun
中科院分区：
文献类型：
--
作者：
Negi, Ankit;Kim, Hwang Pill;Hua, Zilong;Timofeeva, Anastasia;Zhang, Xuanyi;Zhu, Yong;Peters, Kara;Kumah, Divine;Jiang, Xiaoning;Liu, Jun
铁电畴壁的作用类似于热电阻，可以被操纵以实现热导率（k）的动态调制，这对于开发新型声子电路是必不可少的。尽管有兴趣，但由于在获得高热导率切换比（k高/k低）方面的挑战，特别是在商业上可行的材料中，很少关注在体材料中实现室温热调制。在这里，展示了2.5 mm厚的Pb（Mg 1/3 Nb 2/3）O3-xPbTiO 3（PMN-xPT）单晶的室温热调制。利用先进的极化条件，辅助PMN-xPT的成分和取向依赖性的系统研究，观察到的热导率切换比的范围与最大值为1.27。同时测量表征极化状态的压电系数（d33）、使用偏振光显微镜（PLM）的畴壁密度以及使用定量PLM的双折射变化揭示，与未极化状态相比，中间极化状态（0<d33<d33，max）下的畴壁密度由于畴尺寸的增大而较低。在优化的极化条件（d33，最大值），域大小显示增加的不均匀性，导致域壁密度的增强。这项工作突出了市售PMN-xPT单晶在其他弛豫铁电体中实现固态器件温度控制的潜力。
Acting like thermal resistances, ferroelectric domain walls can be manipulated to realize dynamic modulation of thermal conductivity (k), which is essential for developing novel phononic circuits. Despite the interest, little attention has been paid to achieving room‐temperature thermal modulation in bulk materials due to challenges in obtaining a high thermal conductivity switching ratio (khigh/klow), particularly in commercially viable materials. Here, room‐temperature thermal modulation in 2.5 mm‐thick Pb(Mg1/3Nb2/3)O3–xPbTiO3(PMN–xPT) single crystals is demonstrated. With the use of advanced poling conditions, assisted by the systematic study on composition and orientation dependence of PMN–xPT, a range of thermal conductivity switching ratios with a maximum of ≈1.27 is observed. Simultaneous measurements of piezoelectric coefficient (d33) to characterize the poling state, domain wall density using polarized light microscopy (PLM), and birefringence change using quantitative PLM reveal that compared to the unpoled state, the domain wall density at intermediate poling states (0<d33<d33,max) is lower due to the enlargement in domain size. At optimized poling conditions (d33,max), the domain sizes show increased inhomogeneity that leads to enhancement in the domain wall density. This work highlights the potential of commercially available PMN–xPT single crystals among other relaxor‐ferroelectrics for achieving temperature control in solid‐state devices.