Evaluation of the Elastic Constants of an Amorphous-Alloy Thin Film by Using EMAR and RUS/Laser Methods
Akira SHIBATA, Ryuichi TARUMI, Hirotsugu OGI, Masahiko HIRAO, Kazuki TAKASHIMA and Yakichi HIGO
Abstract:We have measured the complete set of elastic moduli Cij of an Fe-Si-B amorphous-alloy thin film using thickness resonance with electromagnetic acoustic resonance（EMAR） and newly developed resonance ultrasound spectroscopy（RUS）/laser ethods. From the thickness-resonance measurements，out-of-plane shear moduli（C44 and C55） were found to be 73.2 and 71.0 (Gpa). This indicates that the amorphous-alloy thin film shows transverse-isotropy elastic symmetry. RUS/laser measurements gave the remaining moduli: C11=193.6, C33=234.3, C23=72.1, C12=79.8, and C44=72.1 (Gpa). From the ratios of the elastic modulus, （C33/C11=1.21 and C44/C66=1.26), the amorphous Fe-Si-B thin film shows elastic anisotropy between in-plane and the out-of-plane directions in the range of 20-30%. These results also indicate that this ultrasonic technique is also applicable for measuring all Cij of other thin films. Key Words:Amorphous alloy, Thin film, Elastic constants, Resonance frequency, Ultrasonic resonance