Simulation Determination of the Electromagnetic Parameters for the CdCr₂S₄ Multiferroic Relaxor in GHz Range

Abstract:

The GHz range is a domain not enough exploited for application in the case of the materials like the CdCr₂S₄ multiferroic which possesses all four properties of colossal magnetoresistance, electroresistance, is colossal magnetocapacitive and electrocapacitive. The 3D simulation by structural description of such a material represents a real challenge of the descriptive simulational science, due to the complexity of the internal phenomena and interactions which occur here. Dielectric and magnetic properties were reported up to 3 GHz by measurements (Hemberger et al. and so on), while our simulation method is coming to extrapolate the results up to 18 GHz for applications in spintronics and microelectronics. The geometrically frustrated thiospinel system, included in the Heisenberg 3D ferromagnets class, was described with help of the HFSS 13.0 program. An algorithm based on physical consideration was used for the material samples simulated inside a rectangular waveguide, in order to determine their complex electromagnetic parameters (electric permittivity and magnetic permeability). Maxima were found on the real permittivity / permeability graph and by overlapping of the graphs, distinctive resonances were separated. Resonances were linked on the internal structure and the exciting field interaction with the material samples, considering that each mechanism of interaction is dominated by the characteristics of the ferroic propriety involved. A structural resonance map for the microwave range up to 18 GHz was represented. The material presenting all four ferroic properties has resonances specific for each property, but also cumulative resonances, of various magnitude, which can be described only by considering two or more ferroic properties characterizing the same material state.

• Periodical: Applied Mechanics and Materials (Volume 371)
• Pages: 389-393
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.371.389
• Online since: August 2013
• Authors: Daniela Ionescu, Maria Kovaci
• Keywords: Microwave, Multiferroic Relaxor, Physical Resonance, Structural Simulation

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