Simultaneous measurement of field dependence of elastic moduli by laser interferometry

A methodology is applied which allows the simultaneous determination of Young's modulus and the shear modulus to evaluate elastic moduli variations with the magnetic field (Delta E and Delta G). The method employed is based on the simultaneous detection of the transverse and torsional natural frequencies of a slender magnetic bar located within a solenoid. The resultant vibration is detected via a heterodyne interferometric optical system with a broad bandwidth. The vibration detection and excitation systems do not interact with the sample. The applicability of the method is demonstrated by characterizing 10-mm-diameter nickel bars. The results are compared with those obtained from longitudinal vibrations, (C) 2000 Elsevier Science B.V. All rights reserved.