Field control of multiferroic spherical core-shell nanocomposites with applications in microwave range

Modern Technologies in Industrial Engineering 2015

Ionescu, D.^1 ; Kovaci, M.^2

Gh. Asachi Technical Univ. of Iasi, Faculty of Electronics Telecommunications and Information Technology, Dept. of Telecommunications, Carol I Blvd., No. 11, Iasi

700506, Romania^1

Politehnica University of Timisoara, Faculty of Electronics and Telecommunications, Dept. of Communications, V. Pârvan Blvd., No. 2, Timisoara

300223, Romania^2

关键词: Applied magnetic fields;    Core-shell nanocomposites;    Different-magnetic fields;    External magnetic field;    Magnetoelectric coefficients;    Nanoparticle structures;    Piezoelectric coefficient;    Spherical nanoparticles;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/95/1/012030/pdf
DOI  :  10.1088/1757-899X/95/1/012030

来源: IOP

【 摘 要 】

Muliferroic spherical nanoparticle configurations consisting of magnetostrictive core encapsulated in piezoelectric shell have been studied. The particles were simulated in a test configuration with help of the HFSS 13.0 (by Ansoft). An external magnetic field H0was applied, which determines the apparition of dipolar electric fields of tens of milivolts around nanoparticle structures, used for tuning and control of different microstructures, at molecular level and in spintronics. The nanoparticle compounds are: an A2BB'O6double perovskite with large piezoelectric coefficients and a MeFe2O4spinel or a AFe12O19M-type hexagonal ferrite with large magnetostriction, resulting in nanoparticle configurations with large magnetoeletric (ME) effect. The strength of the ME effect is also increased by the effect of the closed-packed shape of the spherical core-shell configuration. Different magnetic phases (spinel versus hexaferrite) were considered, in order to determine their influence in the interaction process with the applied magnetic field. The diameter of the piezoelectric shell did not exceeded 300 nm, starting from about 50 nm. The components of the magnetoelectric coefficient tensor and the effective electric and magnetic susceptibilities have been determined by simulation in microwave range (2 - 8 GHz for spinel compounds, respectively 12 - 28 GHz for hexaferrite compounds), for different magnetic fields applied for control (0 - 400 Oe), fields depending on particles size. The tensor components depend on the physical properties of the constituents and also on the constituents geometry and relative position. Nanoparticle configurations geometry and the applied H0field were modified in order to obtain a convenient variation and control of the compound susceptibilities. Graphs are available for choosing the optimal configuration and parameter values for a specific application..