The plastic deformation of amorphous alloys is well known to be localized into shear bands(SBs),which are believed to stem from the atomic-scale flow defects,i.e.,shear transformation zones(STZs).Yet,the bridge between the mesoscopic SBs and the atomic-scale STZs remains poorly understood.In this work,through thermally activating pronounced β relaxations in the well-designed crystalline-layer confined amorphous(CLCA)NiW alloy films,we experimentally captured and observed an intermediate nano-sized structure termed as"nano shear bands"(NSBs)with a typical size of 1-2 nm in thickness and 5-10 nm in length.The influences of such NSB structures on the macroscale deformation behavior were systematically investigated.It was found that NSBs lead to both hardening and toughening effects for the CLCA films,as they promote multiple and controlled shear banding deformation,which results in enhanced crystallization.The intermediate NSB structure could connect the microstructural characteris-tics and macroscopic plasticity in amorphous alloys and may provide new insights for understanding the microscopic deformation mechanism of amorphous alloys as well as tuning/designing their properties.

Songshan Lake Materials Laboratory,Dongguan 523808,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Xinjiang Key Laboratory of Solid State Physics and Devices and School of Physical Science and Technology,Xinjiang University,Xinjiang,Urumqi 830046,China;Key Laboratory of LCR Materials and Devices of Yunnan Province,School of Materials and Energy,Yunnan University,Kunming 650091,China;State-Key Laboratory for Mechanical Behavior of Material,Xi'an Jiaotong University,Xi'an 710049,China;State Key Laboratory for Strength and Vibration of Mechanical Structures,Xi'an Jiaotong University,Xi'an 710049,China;National Demonstration Center for Experimental Mechanics Education,Xi'an Jiaotong University,Xi'an 710049,China

[1]Z.Q.Chen;M.C.Li;X.Tong;Y.Zhao;J.Y.Xie;S.W.Guo;P.Huang;F.Wang;H.B.Ke;B.A.Sun;W.H.Wang-.Hardening and toughening effects of intermediate nanosized structures in a confined amorphous alloy film)[J].材料科学技术（英文版）,2022(23):44-53

STZs,CLCA,NiW,NSBs

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