In Situ Domain Structure Observation and Giant Magnetoelectric Coupling for PMN‐PT/Terfenol‐D Multiferroic Composites

Abstract

In situ observations of ferroelectric domain structure evolution, and magnetoelectric (ME) coupling are investigated for PMN‐28PT/Terfenol‐D (abbreviation of Pb(Mg1/3Nb2/3)O3‐28PbTiO3/Tb0.3Dy0.7Fe2) and PMN‐33PT/Terfenol‐D composites under the magnetic loadings. The composite of PMN‐33PT/Terfenol‐D shows stronger ME coupling than that in PMN‐28PT/Terfenol‐D. At a thickness of 0.10–0.12 mm for the single crystal plate, a giant magnetoelectric coefficient (αME) up to 2 V/cm·Oe is obtained for PMN‐33PT/Terfenol‐D at a static magnetic field of 200 Oe and 1 kHz of the alternating magnetic field. In situ domain structure observations reveal the domain morphology change during the applied magnetic loadings. In PMN‐28PT, the domains are of predominantly rhombohedral (R) phase and they change into monoclinic MA phase upon the magnetic loading via the strain transferred between Terfenol‐D plate and PMN‐PT single crystal. In PMN‐33PT, domains of orthorhombic (O), R, and monoclinic MC coexist and phase transitions from O to MC and further to R phase occur upon the magnetic loading. The undulation and diversity of the domain structure makes the domains more susceptible to the magnetic loading via strain transferred between Terfenol‐D plate and PMN‐PT single crystal, and consequently, a strong ME coupling in the composites.

Multi‐scale domain structure observation and piezoelectric responses for [001]‐oriented PMN‐33PT single crystal

“…Regular domain bands appear in M-phase regions, which are in consistence with many previous studies. 16,21,24,25,30,31 However, irregular domain boundaries also appear in M-phase regions, as the morphology of the domain structure is related with the lowest energy state. 21 Examination on Figure 5A and B reveals that the adjacent domains labeled as "A" and "B" have a phase contrast of 180°.…”

“…For characterization of ferroelectric domain or domain boundary structures, a variety of techniques have been employed, such as X-ray and neutron diffraction techniques, 15,22 transmission electron microscopy (TEM), 19 polarized light microscopy (PLM), 16,[23][24][25] and PFM. [25][26][27][28] Using PFM, Zeng et al 26 Although PFM is capable of revealing the domain morphologies in nanoscale, and measuring the piezoelectric response of individual domains simultaneously, it is unable to detect the phase symmetry of the ferroelectric domains.…”

Magnetic field-induced ferroelectric domain structure evolution and magnetoelectric coupling for [110]-oriented PMN-PT/Terfenol-D multiferroic composites

“…However, this value is much lower than the [100]-oriented counterpart, which is 2V/cm·Oe. 29 For composites of PMN-28PT/Terfenol-D and PMN-33PT/Terfenol-D, the different ME coupling behavior depends on the piezoelectricity of PMN-28PT and PMN-33 PT single crystals. Supposing σ is the stress transfer between the Terfenol-D plate and the PMN-PT single crystal, the ME coefficient α ME of the composites can be evaluated from 29 Where d 31,p is the piezoelectric constant of the single crystal with the induced polarization in the thickness direction upon the applied longitudinal stress.…”

“…Recently, the authors observed the polarization rotation from R to M A for [001]-oriented PMN-28PT/Terfenol-D composite, and from O to M C and then to R for the [001]-oriented PMN-33PT/Terfenol-D composite under the applied magnetic loadings. 29 The later possesses a magnetoelectric coefficient (α ME ) up to 2 V/cm·Oe at a static magnetic field of 200 Oe and 1 kHz of the alternating magnetic field. 29 By using piezoresponse force microscopy, Miao et al 30 reported the magnetic-field-induced ferroelectric polarization reversal in bilayer Terfenol-D/PMN-33PT composite.…”

“…29 The later possesses a magnetoelectric coefficient (α ME ) up to 2 V/cm·Oe at a static magnetic field of 200 Oe and 1 kHz of the alternating magnetic field. 29 By using piezoresponse force microscopy, Miao et al 30 reported the magnetic-field-induced ferroelectric polarization reversal in bilayer Terfenol-D/PMN-33PT composite. In this study, the ME composites are prepared by cementing together thin sheet of [110]-oriented PMN-PT single crystal and Terfenol-D plate using epoxy resin.…”