Effect of the effective anisotropy field of soft layer on magnetic properties of soft/hard stacked media

Effective reduction of the coercivity for Co$_{72}$Pt$_{28}$ thin film by exchange coupled Co$_{81}$Ir$_{19}$ soft layer with negative magnetocrystalline anisotropy

“…Thus, by oriented-growth of the hcp-Co 81 Ir 19 (negative MA with x = 19) layer with its crystallographic c-axis parallel to the normal of the film surface, its magnetic moments can be restricted strictly in-plane by its negative MA, thus providing a very strong negative total in-plane anisotropy for our ECC media 32,33 . A series of samples with different SL thickness and composition were investigated and we will show that negative SL MA is more efficient in reducing the coercivity of the ECC media, thus our results agree with the theoretical prediction of Victora et al 12,29 and open a new playground for further improvements of the magnetic properties of the ECC media for high density magnetic recording.…”

“…The data have been normalized to the value of the most right side data point at K s =-3.5×10 5 J/m 3 for better comparison with calculations. The enhanced reduction with decreasing K s is inconsistent with the predictions by Suess et al 11 ; however being in agreement with the results of Victora et al 12,29 .…”

“…11 ). On the other hand, using the model proposed by Victora et al 29 , Wang et al 12 have shown that negative SL anisotropy actually has a beneficial contribution in decreasing the switching field. To resolve the different theoretical predictions between Suess et al and Victora et al and to further optimize the magnetic properties of the ECC media, it is very interesting to experimentally investigate how does negative SL MA affect the coercivity of the ECC system.…”

“…Among them, the ECC media, in the form of magnetically hard/soft multi-layer structure, have attracted much attention due to their promising potential in resolving the above mentioned trilemma challenge [1][2][3][4] . Extensive theoretical work have been performed to investigate the effects of soft-layer (SL) thickness 8,9 , anisotropy constant [10][11][12] , hard-to-soft layer coupling strength 3,[13][14][15] , and the magnetization reversal process 14,16,17 . Experimentally, many work have been realized with FePt [18][19][20][21][22][23] , CoPt [24][25][26][27][28] due to their high uniaxial magnetocrystalline anisotropy (MA) which is essential to maintain high thermal stability in high density magnetic recoding.…”

Electrochemical preparation and magnetic properties of submicrometric core–shell CoPt–CoNi particles

“…These systems can combine the high magnetization of soft phase with the coercivity of hard phase to attain a high energy product to obtain a maximum magnetic energy product [17]. A system is recognized as an exchange spring magnet when both phases are coupled to each other [18,19]. In this case, the high saturation magnetization of the soft phase and the high coercivity of the hard phase confer better magnetic properties of the composite compared to the individual soft and hard phases, thus providing high magnetic energy product [20].…”