eng Science and Education Publishing Journal of Materials Physics and Chemistry 2333-4444 2018-10-23 6 2 36 38 10.12691/jmpc-6-2-1 JMPC2018621 article A. Adanlété Adjanoh adanlete.assiongbon@gmail.com 1 R. Belhi 2 Département de Physique, Faculté des Sciences et Techniques, Université de Kara, B.P : 404, Kara, Togo Département de Physique, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 1060, Tunisia We present the detailed study of activation energy Ea according to the thickness of the magnetic layer (tCo=0.7,0.8 and 1nm). The study was carried out at room temperature by means of polar magneto-optical Kerr effect magnetometry (PMOKE) using a He-Ne laser (=633nm). We found that the activation field 0Ha, the coercive field 0HC and the average activation energy Ea are weak for the sample with thickness tCo = 1 nm. http://pubs.sciepub.com/jmpc/6/2/1/jmpc-6-2-1.pdf time of demagnetization activation field activation energy activation volume