Title :
Thermoreflection Measurement of Magnetic Thin Films
Author :
Yang, Hang Zhou ; Leong, S.H. ; An, C.W. ; Chen, Y.J. ; Ye, K.D. ; Ng, L.T. ; Zhang, Juyong ; Ng, Kang Kee ; Hu, Jiang Feng
Author_Institution :
Data Storage Inst., Agency for Sci., Technol. & Res. (A*STAR), Singapore, Singapore
Abstract :
With recent developments in heat assisted magnetic recording (HAMR), there is growing intense interest in understanding the thermal-optical properties of the HAMR media. We study the phase change of the optical beam as it reflects from a FePt thin film under strong laser irradiation by carrying out close-aperture reflection Z-scan experiments. It is found that the far field spatial distribution of the reflected beam is sensitively dependent on the thermal field distribution in the media. We also carry out a temperature dependent pump-probe experiment to study the variation of the differential thermoreflection signal with different media temperature. It is found that the differential signal is sensitively dependent on the media temperature. The present studies show potential to enable noncontact temperature measurement of HAMR media and detect the spatial distribution of the thermal field in the HAMR media.
Keywords :
iron alloys; laser beam effects; magnetic recording; magnetic thin films; metallic thin films; platinum alloys; thermomagnetic effects; thermoreflectance; FePt; HAMR media; close-aperture reflection Z-scan experiments; differential thermoreflection signal; far field spatial distribution; heat assisted magnetic recording; laser irradiation; magnetic thin films; media temperature; noncontact temperature measurement; optical beam; reflected beam; temperature dependent pump-probe experiment; thermal field distribution; thermal-optical properties; thermoreflection measurement; Complex refractive index; close-aperture Z-scan; heat assisted magnetic recording (HAMR); pump-probe; thermoreflection;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2013.2256774
