Jinyu Yan
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Jinyu Yan has a total of 6 co-authors. Here are the top co-authors by number of shared publications:
- Chuanwei Li
Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
1 shared publication - Jun Li
School of Mechanical Engineering, University of South China, 28 West Changsheng Road, Zhengxiang District, Hengyang 421001, China
1 shared publication - Linan Li
Department of Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China
1 shared publication - Shibin Wang
Tianjin Univ. (China)
1 shared publication - Xinhao Tu
Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
1 shared publication - Zhiyong Wang
Tianjin University
1 shared publication
Latest Publications
- Open Access
Picosecond Ultrasonics for Studying Elastic Modulus of Polycrystalline Chromium Nanofilms: Thickness Dependence and Stiffness Enhancement
Accurate measurement of elastic constants in thin films is still an important issue to understand the scale behavior of nanosized materials. In the present study, we introduced an advanced non-destructive method, picosecond ultrasonics (PU), for measuring the out-of-plane elastic modulus of thin chromium (Cr) films. The femtosecond light pulse is focused on the Cr film to excite the longitudinal acoustic phonons (LAP), which propagate along the thickness direction and repeat reflections inside the Cr film. Then, the propagation/distribution of LAP is detected by the time-delayed probe light pulse through the photoelastic effect. Therefore, we can determine the out-of-plane modulus by measuring the periodic pulse echoes or the breathing mode vibrations within the Cr film. For most Cr films, the determined modulus is smaller than the corresponding bulk value and decreases with the decreasing thickness, while for some Cr films, it closes and may exceed the bulk value. This work describes the thickness-dependent elasticity of thin Cr films and provides evidence of the stiffness enhancement in Cr films on the Si substrate. In addition, since LAP with central frequency up to 310 GHz is excited in Cr films on the SiO2 substrate, we also demonstrate the potential of Cr films as high-frequency photoacoustic transducers.
Open AccessPicosecond Ultrasonics for Studying Elastic Modulus of Polycrystalline Chromium Nanofilms: Thickness Dependence and Stiffness Enhancement
Accurate measurement of elastic constants in thin films is still an important issue to understand the scale behavior of nanosized materials. In the present study, we introduced an advanced non-destructive method, picosecond ultrasonics (PU), for measuring the out-of-plane elastic modulus of thin chromium (Cr) films. The femtosecond light pulse is focused on the Cr film to excite the longitudinal acoustic phonons (LAP), which propagate along the thickness direction and repeat reflections inside the Cr film. Then, the propagation/distribution of LAP is detected by the time-delayed probe light pulse through the photoelastic effect. Therefore, we can determine the out-of-plane modulus by measuring the periodic pulse echoes or the breathing mode vibrations within the Cr film. For most Cr films, the determined modulus is smaller than the corresponding bulk value and decreases with the decreasing thickness, while for some Cr films, it closes and may exceed the bulk value. This work describes the thickness-dependent elasticity of thin Cr films and provides evidence of the stiffness enhancement in Cr films on the Si substrate. In addition, since LAP with central frequency up to 310 GHz is excited in Cr films on the SiO2 substrate, we also demonstrate the potential of Cr films as high-frequency photoacoustic transducers.