I. - Magnetization Mechanismssome Physical Considerations About the Domain Wall Size Theory of Magnetization Mechanisms

Enhancement of microstructure and initial permeability due to Cu substitution in Ni0.50−xCuxZn0.50Fe2O4 ferrites

“…f r shifted towards the lower frequency with the increase in Cu 2 þ content or increase in m 0 i . This agrees well with the Globus model [25], which relates the resonance frequency with permeability as (m i -1) 1/2 f r ¼constant. m 0 i of the samples also increases with increase in sintering temperatures because of enhancement of grain size as shown in Fig.…”

Rapid processing of ferrite ceramics with promising magneto-dielectric characteristics

“…When accounting for the permeability of ferrites, two contributions, spin-rotation and domain wall motion, must be considered. According to Globus's model, 16 the portion of permeability contributed by domain-wall-motion is linearly dependent on grain size, while the permeability contributed by spin-rotation is independent of grain size. Figure 7 shows static permeability Conventional antennas for the frequency band of 3-30 MHz (HF) and 30-300 MHz (VHF) are physically large, and therefore not suitable for portable applications.…”

“…A model proposed by Globus 16 can be used to describe the relationship between static permeability and microstructure of the ferrite ceramics. When accounting for the permeability of ferrites, two contributions, spin-rotation and domain wall motion, must be considered.…”

Permeability spectra of yttrium iron garnet and its granular composite materials under dc magnetic field

“…The l 00 r peak frequency shift suggests that the domain wall resonance frequency increases with increasing external dc magnetic field. Globus discussed the contribution of the domain wall motion to the magnetic permeability in ferrites; 21 the domain wall that is pinned to the grain boundary or impurities can vibrate with the external alternating magnetic field and a mechanical resonance of the domain wall vibration can be produced. This resonance produces the resonance type variation of the magnetic permeability.…”

“…Among the ferrites, yttrium iron garnet (YIG) is widely used for high frequency devices and the permeability of YIG has been extensively studied theoretically and experimentally so far. [20][21][22] The complex permeability under external magnetic fields have also been studied and negative permeability spectra have been reported. 23,24 Several LHMs have been constructed using the MNG characteristics of YIG and other ENG materials in the microwave frequency range.…”