Time-resolved reflectometry on free-standing membranes of SrRuO3

The data in this repository involve time-resolved reflectivity measurements on crystals of nanometric thickness. We use nanoscale acoustic confinement to excite coherent acoustic phonons (dynamical strain) with near-terahertz frequency, and demonstrate that such phonons can easily be excited when breaking the film-substrate epitaxy in the metallic perovskite SrRuO3. Moreover, thermal annealing of the free-standing membranes placed on a substrate with a similar lattice constant dramatically decreases the interfacial acoustic impedance mismatch, evidencing the reformation of chemical bonds and interfacial restructuring.本仓库所收录的数据，针对纳米级厚度晶体开展了时间分辨反射率测量（time-resolved reflectivity measurements）。我们采用纳米尺度声学约束（nanoscale acoustic confinement）技术，激发了频率处于近太赫兹频段（near-terahertz frequency）的相干声学声子（coherent acoustic phonons，即动态应变（dynamical strain）），并证实：在金属钙钛矿型钌酸锶（SrRuO3）中破坏薄膜与衬底的外延关系时，可轻易激发此类声子。此外，将自立式薄膜放置在晶格常数相近的衬底上进行热退火（thermal annealing）处理，可显著降低界面声学阻抗失配（interfacial acoustic impedance mismatch），印证了化学键重组与界面重构（interfacial restructuring）过程。