Enregistrement thermomagnétique sous pointe AFM: vers les ultrahautes densités d'enregistrement

Abstract : This thesis aims to propose a new method of mass storage on hard disks and to prove its feasibility. Thermomagnetic probe recording consists in combining the effect of a near field heating with a macroscopic magnetic field to switch locally the magnetization on a patterned magnetic media.
The first of the work was to determine conditions for which temperature reached on media are sufficient(400-450K) to switch magnetization under low applied magnetic field. Thermal simulations showed the necessity to use a patterned insulator substrate to reduce heat losses by conduction.
The porous silicon thermal conductivity can be as low as 0.14 W.m-1.K-1 with a 70% porosity ratio. A porous layer is formed in a patterned silicon substrate. The Magnetic properties of Co/Pt multilayers and amorphous alloys of TbFeCo deposited on porous silicon and on patterned porous silicon were studied.
AFM heating tips were fabricated from commercial AFM probe to be adapted to a AFM microscope. Despite their high power consumption and their slow response time, they can be heated up to high temperatures. On another hand, a commercial AFM microscope has been customized to realize thermomagnetic writing tests. First tests demonstrated the manipulation of a single dot magnetization. New efforts should be realized to allow systematic and reproducible writing procedure.
An experimental set up has been developed to measure heat exchanges between an AFM tip and a surface. First promising results have been obtained and different heat transfer regime have been observed.
Document type :
Condensed Matter [cond-mat]. Université Joseph-Fourier - Grenoble I, 2006. French

Contributor : Emmanuelle Algre <>
Submitted on : Wednesday, August 16, 2006 - 3:29:04 PM
Last modification on : Thursday, April 23, 2015 - 1:49:27 PM
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  • HAL Id : tel-00089261, version 1



Emmanuelle Algre. Enregistrement thermomagnétique sous pointe AFM: vers les ultrahautes densités d'enregistrement. Condensed Matter [cond-mat]. Université Joseph-Fourier - Grenoble I, 2006. French. <tel-00089261>




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