Electric-field manipulation of coercivity in FePt/Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃heterostructures investigated by anomalous Hall effect measurement

Abstract

The effect of electric field (E-field) on the magnetism of FePt thin films in FePt/0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 (PMN–PT) heterostructures was investigated by anomalous Hall effect measurement. For FePt films of different thicknesses, the coercivity vs E-field curves show a typical butterfly-like loop behavior. Further results indicate that the coercivity variation is composed of the volatile symmetrical butterfly-like loop and nonvolatile hysteresis loop-like parts, which originate from the volatile and nonvolatile strains induced by the E-field in the PMN–PT(001) substrate, respectively. No significant difference has been observed after inserting a 2 nm W interlayer, suggesting that the charge-mediated coercivity variation is negligible in FePt/PMN–PT heterostructures.

Strain-Mediated Coexistence of Volatile and Nonvolatile Converse Magnetoelectric Effects in Fe/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 Heterostructure

“…Hence, a moderate magnetocrystalline anisotropy with designed in-plane orientation may serve as the third approach to electric-field control of the nonvolatile 180° magnetization reversal, without additional fabrication costs for the patterned nanomagnet or an induced antiferromagnetic pinning layer . Finally, we would like to mention that although the charge-mediated nonvolatile ME effect has already been confirmed in complex oxides with a low carrier density and ultrathin FM metal, it is negligible for our 20 nm thick Fe film because it is effective only within 1–2 unit cells near the interface. , Nevertheless, charge and strain comediated coexistence of volatile and nonvolatile magnetization is still accepted and under discussion in similar FM/FE structures. − A full understanding of the converse ME effects in multiferroic heterostructures is awaited.…”

Electric Field Manipulated Multilevel Magnetic States Storage in FePt/(011) PMN-PT Heterostructure

“…24−26 As for the FM component, we choose the binary alloy, FePt, due to its large magnetic anisotropy and magnetostriction constant. 27,28 We demonstrate that multiple M r states can be reversibly written as storage data bits in a FePt/PMN-PT heterostructure by electric field. These magnetic signals are nonvolatile and steady enough to retain written information.…”

“…In this article, a (011)-oriented 0.7Pb­(Mg 1/3 Nb 2/3 )­O 3 -0.3PbTiO 3 (PMN-PT) single crystal is selected as a FE substrate for its electric field controlling reversible and nonvolatile strain with the application of electric field. − As for the FM component, we choose the binary alloy, FePt, due to its large magnetic anisotropy and magnetostriction constant. , We demonstrate that multiple M r states can be reversibly written as storage data bits in a FePt/PMN-PT heterostructure by electric field. These magnetic signals are nonvolatile and steady enough to retain written information.…”

Magnetic properties of L 1 0 FePt thin film influenced by recoverable strains stemmed from the polarization of Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 substrate

“…Nevertheless, one experimental work [23] showed that the value of coercivities increased with the increase of the recoverable compressive misfit strain in the L1 0 FePt (3 nm) thin film deposited on PMN-PT substrate. The reason is that when the PMN-PT substrate is polarized under an applied electric field, a recoverable strain is induced by a converse piezoelectric effect, which can pass on to the L1 0 FePt thin film and thus manipulate the magnetic anisotropy of the film through the converse magnetostriction effect.…”