（中国科学技术大学 合肥微尺度物质科学国家研究中心） 

Abstract: Phase boundary, the interface between neighboring physical phases in matters, hosts various emergent novel phenomena and has been the pivotal subject of research interest for decades. Conventional techniques for the spatial resolving of phase boundary rely on the interaction between the sample and certain probing particle, e.g. photon or electron, in which smooth surface or high vacuum is usually required. Here we show that a phase boundary on a surface out of flatness can be resolved by the lock-in thermography in ambient environment, where a photon or electron beam as probe is not employed. An alternating charge current is applied through the sample and the phase boundary is revealed by the Peltier effect induced periodical temperature modulation of few-mK amplitude [1,2]. We visualize the phase boundary evolution in bulk NiTi wires and ultrathin FeRh film during the phase transition by lock-in thermography, demonstrating the versatility and the potential for wide application, e.g., the spatial phase distribution mapping and in-situ non-destructive defectoscopy.

Reference:

[1] Hilmar Straubea, Jan-Martin Wagner, and Otwin Breitenstein, Appl. Phys. Lett. 95, 052107 (2009)

[2] K. Uchida, S. Daimon, R. Iguchi et al. Observation of anisotropic magneto-Peltier effect in nickel. Nature 558, 95–99 (2018)

报告人简介：

   主要从事凝聚态材料中的自旋相关物理现象的研究与探索、自旋相关电磁热输运性质测量。国际重要学术期刊上已发表论文共34篇，其中第一作者或通讯作者文章10篇，包括Nature Materials 1篇， Physical Review Letters 3篇，Nature Communications 2篇，ASC nano 1篇，NPG Asia Materials综述论文1篇，总引用数1440次（Google Scholar）。担任Nature Physics, Nature Communications, Physical Review Letters ，Advanced Materials等杂志审稿人。

Publications:

1. Jinhui Shen, Zheng Feng, Dazhi Hou^*, Xiaofeng Jin^* et al. Phys. Rev. Lett. 126 (19), 197201, (2021).
2. Zhiyong Qiu, Dazhi Hou^* et al. Nat. Mater. 17(7), 577(2018).
3. Dazhi Hou, Z. Qiu^*, Joseph Barker et al. Phys. Rev. Lett. 118(14), 147202 (2017).
4. Dazhi Hou*, Zhiyong Qiu, E. Saitoh et al. Nat. Commun. 7, 12265 (2016).
5. Zhiyong Qiu, Dazhi Hou^*, Eiji Saitoh et al. Nat. Commun. 7, 12670 (2016).
6. Dazhi Hou, Xiaofeng Jin^*, Q. Niu* et al. Phys. Rev. Lett. 114(21), 217203 (2015).

邀请人：胡凤霞（82649233）