Complex permeability and permittivity, and microwave absorption studies of Ca(CoTi)xFe12−2xO19 hexaferrite composites in X-band microwave frequencies

Singh, Praveen; Babbar, V. K.; Razdan, Archana; Srivastava, Shivani; Puri, R. K.

doi:10.1016/s0921-5107(99)00328-1

Cited by 66 publications

(34 citation statements)

References 12 publications

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“…where σ w is domain wall energy and Ms is saturation magnetization for the given sample [26]. The prepared in this experiment higher substitution ferrites are multi-domain and there is magnetic loss due to the displacement of domain walls.…”

Section: Resultsmentioning

confidence: 98%

Complex permittivity, permeability and microwave absorbing properties of Co–Ti substituted strontium hexaferrite

Narang

Kaur

Bahel

2016

Materials Science-Poland

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M-type strontium ferrite with compositions SrFe (12−2x) Co x Ti x O 19 (x = 0.0, 0.3, 0.5, 0.7, 1.0), were prepared by two route ceramic method. The effects of Co-Ti substitution on their microstructure, electromagnetic properties, and microwave absorptive behavior were analyzed. The complex permittivity (ε -jε ) and complex permeability (µ -jµ ) have been measured from 8.2 to 12.4 GHz using a network analyzer. Scanning electron microscope was used to analyze the grain size distribution and porosity of the ferrite. X-ray diffraction confirmed the M-type structure of the doped strontium ferrite. Vibrating sample magnetometer was used to study hysteresis loop of the ferrite. This study suggests that the control of grain size, decrease in coercivity and enhanced values of dielectric constant and loss are effective means to improve microwave absorption. The dielectric constant and loss were enhanced in comparison to the permeability constant and loss over the entire frequency range.

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Section: Resultsmentioning

confidence: 98%

Complex permittivity, permeability and microwave absorbing properties of Co–Ti substituted strontium hexaferrite

Narang

Kaur

Bahel

2016

Materials Science-Poland

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“…Esta hexaferrita foi preparada neste estudo com a incorporação intencional dos íons CoTi e La, na empresa Sontag/SP. Essa amostra foi obtida com sucesso pelo processo de metalurgia do pó, conforme procedimento descrito na literatura (Singh et al, 1999).…”

Section: Materiaisunclassified

“…Esses resultados e as baixas perdas na inversão do campo magnético (magnetização remanescente igual a 43,73 Am 2 /kg) indicam que a ferrita de Ca caracterizada trata-se de um material magnético mole. Assim, esses resultados confirmam que a modificação da hexaferrita de Ca, pela incorporação dos íons CoTi e La na sua estrutura, favoreceu o seu amolecimento, em concordância com a literatura (Singh, et al, 1999), deslocando, provavelmente, a sua ressonância natural para frequências mais baixas. componente real da permissividade (ε r ' -componente de armazenamento) e menos significativo do componente imaginário (ε r " -componente de perdas).…”

Section: Atenuação Da Radiação (Db)unclassified

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Comportamento eletromagnético de materiais absorvedores de micro-ondas baseados em hexaferrita de Ca modificada com íons CoTi e dopada com La

Silva¹,

Pereira²,

Nohara³

et al. 2009

JATM

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“…For such purpose materials with high dielectric constant like ZnO, SiO 2 , TiO 2 , BaTiO 3 , or high magnetic permeability, for example, carbonyl iron, Ni, Co, or Fe metals, -Fe 2 O 3 , Fe 3 O 4 , and so forth are used [1,13]. However, these materials or their composites possess problems like low permittivity or permeability at gigahertz frequencies, weight penalties, narrow-band action, and processing difficulties [1,3,13,14]. Other than reflection and absorption, another mechanism of shielding is multiple reflections, which refer to the reflections at various surfaces or interfaces in the shield [1].…”

Section: Introductionmentioning

confidence: 99%

Permittivity and Electromagnetic Interference Shielding Investigations of Activated Charcoal Loaded Acrylic Coating Compositions

Khan

Arora

Wahab

et al. 2014

Journal of Polymers

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Acrylic resin (AR) based electromagnetic interference (EMI) shielding composites have been prepared by incorporation of up to 30 wt% activated charcoal (AC) in AR matrix. These composites have been characterized by XRD, Raman spectroscopy, scanning electron microscopy, dielectric, and EMI shielding measurement techniques. XRD patterns and Raman studies confirm the incorporation of AC particles inside AR matrix and suggest possible interactions between phases. The SEM images show that incorporation of AC particles leads to systematic change in the morphology of composites especially the formation of porous structure. The dielectric measurements show that 30 wt% AC loading composite display higher relative permittivity value (∼79) compared to pristine AR (∼5). Further, the porous structure, electrical conductivity, and permittivity value contribute towards EMI shielding effectiveness value of −36 dB (attenuation of >99.9% of incident radiation) for these composites, thereby demonstrating their suitability for making efficient EMI shielding coatings.

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Complex permeability and permittivity, and microwave absorption studies of Ca(CoTi)xFe12−2xO19 hexaferrite composites in X-band microwave frequencies

Cited by 66 publications

References 12 publications

Complex permittivity, permeability and microwave absorbing properties of Co–Ti substituted strontium hexaferrite

Complex permittivity, permeability and microwave absorbing properties of Co–Ti substituted strontium hexaferrite

Comportamento eletromagnético de materiais absorvedores de micro-ondas baseados em hexaferrita de Ca modificada com íons CoTi e dopada com La

Permittivity and Electromagnetic Interference Shielding Investigations of Activated Charcoal Loaded Acrylic Coating Compositions

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