Agranat M B, Chefonov O V, Ovchinnikov A V, Ashitkov S I, Fortov V E, Kondratenko P S
Joint Institute for High Temperatures of the Russian Academy of Sciences (JIHT RAS), Izhorskaya 13 Building 2, Moscow 125412, Russian Federation.
Nuclear Safety Institute of the Russian Academy of Sciences (NSI RAS), Bolshaya Tul'skaya Street 52, 115191 Moscow, Russian Federation.
Phys Rev Lett. 2018 Feb 23;120(8):085704. doi: 10.1103/PhysRevLett.120.085704.
We report on the experimental observation of high-power terahertz-radiation-induced damage in a thin aluminum film with a thickness less than a terahertz skin depth. Damage in a thin metal film produced by a single terahertz pulse is observed for the first time. The damage mechanism induced by a single terahertz pulse could be attributed to thermal expansion of the film causing debonding of the film from the substrate, film cracking, and ablation. The damage pattern induced by multiple terahertz pulses at fluences below the damage threshold is quite different from that observed in single-pulse experiments. The observed damage pattern resembles an array of microcracks elongated perpendicular to the in-plane field direction. A mechanism related to microcracks' generation and based on a new phenomenon of electrostriction in thin metal films is proposed.
我们报告了在厚度小于太赫兹趋肤深度的薄铝膜中，高功率太赫兹辐射诱导损伤的实验观察结果。首次观察到单太赫兹脉冲在薄金属膜中产生的损伤。单太赫兹脉冲诱导的损伤机制可归因于薄膜的热膨胀，导致薄膜与基底脱粘、薄膜开裂和烧蚀。在低于损伤阈值的通量下，多个太赫兹脉冲诱导的损伤模式与单脉冲实验中观察到的模式有很大不同。观察到的损伤模式类似于垂直于面内场方向拉长的微裂纹阵列。提出了一种与微裂纹产生相关的机制，并基于薄金属膜中的一种新的电致伸缩现象。
