Tunable Microwave Frequency Performance of Nanocomposite Co<SUB>2</SUB>MnSi/PZN-PT Magnetoelectric Coupling Structure

Abstract

Nanocrystalline Co2MnSi Heusler alloy films were deposited on the PZN-PT substrates by a composition gradient sputtering method. It is revealed that this multiferroic heterostructure shows very strong magnetoelectric coupling, leading to continuously tunable microwave frequency characteristics by electric field. With the increase of electric field intensity from 0 to 6 kV/cm, the magnetic anisotropy field H(K) increases from 90 Oe to 182 Oe with an increment of 102%, corresponding to a ME coefficient of 15.3 Oe cm/kV; the ferromagnetic resonance frequency f(FMR) shifts from 3.38 to 4.82 GHz with an increment of deltaf(FMR) = 1440 MHz or deltaf(FMR)/f(FMR) = 43%; moreover, the damping constant alpha dramatically decreases from 0.035 to 0.018. These merits demonstrate that this nanocomposite multiferroic structure is promising in fabrication of tunable microwave components.

E-Field Tuned Rotation of Magnetic Anisotropy and Enhanced Microwave Performance in FeCoAlO/PZN–PT Multiferroic Composite Prepared by Composition Gradient Sputtering

“…It is exciting that the peak frequency of S21 along T direction dramatically increases from 5.2 to 9.0 GHz with nearly 4 GHz increment when the E-field is higher than 4 kV/mm, where the ME-UMA is dominant. Comparison with our previous work with resonance frequency shift from 4.0 to 6.5 GHz in Fe 50 Co 50 -Hf/PZN-PT [35], from 4.2 to 6.7 GHz in Fe 59.3 Co 28 Hf 12.7 / PZN-PT [36], and from 3.38 to 4.82 GHz in Co 2 MnSi/ PZN-PT [25], a relatively large frequency shift was observed in this paper. This fact indicates that the ME coupling is an effective way to enhance the ferromagnetic resonance frequency.…”

“…This geometrical structure makes sure that the compositions from Fe 50 Co 50 target are distributed homogeneously across the sample, while the compositions from Al 2 O 3 target will have a gradient which increases gradually from inner (I) to outer (O) along the radial orientation. [15], and an EA along R direction will be induced by the E-field due to the ME coupling between SMFs and the PZN-PT substrate [25]. Consequently, an orthogonal biaxial magnetic anisotropy is formed in this multiferroic composite.…”