Electrodeposited anisotropic NiFe 45/55 thin films for high-frequency micro-inductor applications

Shape-independent permeability model for uniaxially-anisotropic ferromagnetic thin films

“…The permeability of a uniaxially-anisotropic magnetic thin film, however, has been seen to deviate with film shape from that of an as-deposited thin film. 6 This has been observed for measured samples, 7 however, the general-case relationship has yet to be defined. The thickness-dependence of permeability has additionally been shown in the micron-scale for different ferromagnetic materials such as CoTaZr 8 and NiFe.…”

“…͑7͒. To confirm this, a set of electrodeposited Ni 45 Fe 55 samples 6 of varying thicknesses and constant AR was analyzed with the easy magnetic axis along x. The saturation magnetization of these samples is 1.15ϫ 10 6 A / m and the material anisotropy is 1073 A/m as measured from hysteresis curves and corrected for shape using Eq.…”

“…The thickness-dependence of permeability has additionally been shown in the micron-scale for different ferromagnetic materials such as CoTaZr 8 and NiFe. 6 Previous studies, however, have not provided a detailed analysis of the demagnetization effect and instead focused on experimental curve-fitting. 6 This work presents an analytic three-dimensional ͑3D͒ model for the initial permeability of an in-plane, uniaxially-anisotropic thin magnetic film, based on the intrinsic material anisotropy and the shape-demagnetization effect described by the rectangular prism model.…”

“…6 Previous studies, however, have not provided a detailed analysis of the demagnetization effect and instead focused on experimental curve-fitting. 6 This work presents an analytic three-dimensional ͑3D͒ model for the initial permeability of an in-plane, uniaxially-anisotropic thin magnetic film, based on the intrinsic material anisotropy and the shape-demagnetization effect described by the rectangular prism model. 9 The model is used to analyze the materialindependent effects of film geometry and thickness on permeability and verified for different induced anisotropies and saturation magnetizations by comparison to measured results for CoPRe and NiFe thin films.…”

Integrated Magnetic MEMS Relays: Status of the Technology

“…Magnetic actuation requires the magnetisation of movable structures, which are then attracted to the magnetising source or to other external bias field sources. It is important to be able to control and monitor the properties of micromachined magnetic materials [90][91][92][93][94] in order to ensure that the designed structures enter the desired magnetic states during the switch operation (e.g., magnetisation/demagnetisation to temporarily exert an actuation force, or magnetisation in opposite directions under a constant bias field to switch between attraction and repulsion). Section 4 illustrates a series of MEMS devices with different magnetic configurations.…”