Disordered Nanoparticle Packings under Local Stress Exhibit Avalanche-Like, Environmentally Dependent Plastic Deformation
Disordered Nanoparticle Packings under Local Stress Exhibit Avalanche-Like, Environmentally Dependent Plastic Deformation
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无序纳米颗粒填料在局部应力下表现出类雪崩、环境依赖性塑性变形
DOI：
10.1021/acs.nanolett.8b01640
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发表时间：
2018
期刊：
影响因子：
10.8
通讯作者：
Carpick, Robert W.
中科院分区：
文献类型：
--
作者：
Lefever, Joel A.;Mulderrig, Jason P.;Hor, Jyo Lyn;Lee, Daeyeon;Carpick, Robert W.
在原子力显微镜和透射电子显微镜下对无序纳米颗粒堆积物进行了纳米压痕实验，研究了纳米颗粒堆积物的塑性变形机理。在施加的载荷下，这些高度多孔的膜表现出载荷下降，其幅度与指数总体分布一致。这些负载下降归因于少量颗粒的局部重排，其与剪切转变区和T1过程具有相似性，这两者都是先前预测的无序填料。相对湿度的增加导致所观察到的载荷下降的数量增加，这表明颗粒相互作用的强度对塑性变形的模式有显著影响。这些结果表明，无序的纳米粒子包装可能会在不同的环境下运行的设备中预期的行为。
Nanoindentation experiments on disordered nanoparticle packings performed both in an atomic force microscope andin situin a transmission electron microscope are used to investigate the mechanics of plastic deformation. Under an applied load, these highly porous films exhibit load drops, the magnitudes of which are consistent with an exponential population distribution. These load drops are attributed to local rearrangements of a small number of particles, which bear similarities to shear transformation zones and to the T1 process, both of which have been previously predicted for disordered packings. An increase in the relative humidity results in an increase in the number of observed load drops, indicating that the strength of the particle interactions has a significant effect on the modes of plastic deformation. These results suggest how disordered nanoparticle packings may be expected to behave in devices operating under varying environments.