Anomalous refinement and uniformization of grains in metallic thin films  

作　　者：Lei Wang Shu Wang Xiaofeng Wang Jianming Zhang Jianjie Dong Bin Wei Haiguang Yang Zhongchang Wang Ziyang Zhang ChuanFei Guo Qian Liu 

机构地区：[1]Chinese Academy of Sciences(CAS)Key Laboratory of Nanosystem and Hierarchical Fabrication,CAS Center for Excellence in Nanoscience,National Center for Nanoscience and Technology&University of Chinese Academy of Sciences,Beijing 100190,China [2]College of Mathematics and Physics,Qingdao University of Science and Technology,Qingdao 266061,China [3]Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen 518055,China [4]School of Materials,Sun Yat-Sen University,Guangzhou 510275,China [5]International Iberian Nanotechnology Laboratory(INL),Department of Quantum and Energy Materials,Braga 4715-330,Portugal [6]School of Electronic and Information Engineering,Qingdao University,Qingdao 266071,China [7]The MOE Key Laboratory of Weak-Light Nonlinear Photonics and TEDA Applied Physics Institute and School of Physics,Nankai University,Tianjin 300457,China

出　　处：《Nano Research》2023年第12期13358-13365,共8页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.51971070,T2225017,and 10974037);the National Key Research and Development Program of China(No.2016YFA0200403);the Natural Science Foundation of Shandong Province(No.ZR2021QF003);the CAS Strategy Pilot Program(No.XDA 09020300);the Eu-FP7 Project(No.247644).

摘　　要：When a laser beam writes on a metallic film,it usually coarsens and deuniformizes grains because of Ostwald ripening,similar to the case of annealing.Here we show an anomalous refinement effect of metal grains:A metallic silver film with large grains melts and breaks into uniform,close-packed,and ultrafine(~10 nm)grains by laser direct writing with a nanoscale laser spot size and nanosecond pulse that causes localized heating and adaptive shock-cooling.This method exhibits high controllability in both grain size and uniformity,which lies in a linear relationship between the film thickness(h)and grain size(D),D∝h.The linear relationship is significantly different from the classical spinodal dewetting theory obeying a nonlinear relationship(D∝h5/3)in common laser heating.We also demonstrate the application of such a silver film with a grain size of~10.9 nm as a surface-enhanced Raman scattering chip,exhibiting superhigh spatial-uniformity and low detection limit down to 10-15 M.This anomalous refinement effect is general and can be extended to many other metallic films.

关 键 词：laser direct writing anomalous refinement localized heating RIPENING linear relationship 

分 类 号：TG14[一般工业技术—材料科学与工程]