Magnetostriction Measurement System of Magnetic Thin Films with Michelson Interference

Abstract

  We developed a sensitive magnetostriction measurement system of magnetic thin film specimens using a Michelson interference. When magnetic field is applied parallel to the film plane of the cantilevered specimen, the magnetostriction of the film makes the specimen slightly bend, and the movement of the interference patterns is observed depending on the deflection d of the specimen. Variation of d can be detected with the precision of about one hundredth of wavelength of laser beam. The magnetostriction constant λ₁₁₀ of Fe(001) single crystal thin film deposited on MgO(001) single crystal substrate with film thickness of 61 nm was estimated to be (1. 4±0.27)×10^-5 from the deflection of 2.6±0.5 nm.