In a double layered CoCrTa film separated by a thin flash Cr interlayer, coercivity and coercivity squareness drastically change with increasing the Cr interlayer thickness. There was some coercivity increase in double layered films compared to single layer when the flash Cr interlayer thickness were around 8 to 10A and coercivity decreased with further increase of the Cr interlayer thickness up to 50A. A micromagnetic simulationt technique was employed to understand the coerdvity changes as a function of the interlayer thickness. The simulation results showed fluctuation of coercivity at a thin interlayer thickness range and coercivity becomes a constant value with further increase of the interlayer thickness. These will be discussed.
Magnetic properties of CoCrTa/Cr thin films deposited with DC bias voltage ranging from 0 to -500V were studied. Three different kinds of biasing schemes were used ; Cr layer bias, Co layer bias, Cr and Co layers bias. In all cases, coercivity increased to a maximum value at -300V bias and decreased with further increasing bias voltage. When Cr layers were biased the cause of coercivity increase could not be interpreted by accounting the intensity change of Co (1011), (1010) and (1120) planes only and it is concluded contribution of Cr morphology change on CoCrTa grain separation must be substantial. The increase of coercivity in the CoCrTa biased specimens is understood as enhanced segregation of Cr with the increasing bias voltage. These and other contributions on the coercivity increment will be discussed in detail.
The effect of additional element Cu and Ni into Cr underlayer on a CoCrTa/Cr sputterd thin films was investigated. Cu ad Ni contents effects on the magnetic and structural properties of CoCrTa/Cr was also investigated. The addition of Ni into Cr underlayer made a XRD peak shift to higher 20 indicating the decrease of interplanar distance. It has been shown that the intensity and d-value of Cr(110) peak revealed the different tendency for the increase of the content of Cu and Ni. The increase in coercivity may be resulted from the change of Cr underlayer microstructure, leading to the change of CoCrTa magnetic layer microstructure.
The effect of the under layer on surface smoothness of a simultaneously double coated MP tape was investigated. A smooth surface of the under layer could be obtained by highly dispersing particles in the under layer. The pore volume of the under layer decreases with an increase in the degree of dispersion of the particles. The double-layer coatings showed approximately the same storage modulus, E' values over 100℃ independent of binder resins used, which suggests that they indicate the same viscoelastic behavior at calendering temperature. The surface of the double coated tape with the under layer having a good dispersion of particles was smoother than that of the single magnetic layer. The improvement of electromagnetic characteristics was due to both the reduction of surface roughness and the thinner thickness of the magnetic layer.
Co/Cr and Co/Mo multilayer thin films deposited by the e-beam evaporating method have an alternating layered structure. The structure of film with thicker Co layers than Cr and Mo layers are found to be a hcp structure with the c-axis normal to the film plane. The direction of the film plane is the easy magnetization one. There is a no significant difference in shape of hysteresis loops between Co/Cr and Co/Mo multilayer films. Mo layer is more effective than Cr for preparing Co layer with c-axis normal to the film plane.
Co/Pd and Co/Pt multilayers wilt Pd or Pt base layers were prepared by rf magnetron sputtering and the effects of sputtering pressure during the formation of base layers on the magneto-optical properties of multilayers were investigated. It has been found that coercivity of Co/Pd multilayers was strongly dependent on the sputtering pressure of base layer and could be enhanced to a great extent without noticeable change of Kerr rotation angle by increasing the sputtering pressure of base layer. On the contrary, it turned out that the deposition pressure of base layer gave a little effect on the coercivity of Co/Pt multilayers. For the both multilayers, rectangularity of M-H curves became bad as the deposition pressure of base layer increased.