Tailoring the interfacial magnetic anisotropy in multiferroic field-effect devices

Abstract

Ferroelectric field-effect devices based on perovskite oxide materials offer a new possibility to exploit emergent interfacial effects such as the electrostatic modification of the transport and magnetic properties of strongly correlated materials and to prove the magneto-electric coupling at the interface between the two different ferroic materials. Here we report on the reversible modulation of the interfacial magnetic and magnetotransport properties of La 0.825 Sr 0.175 MnO 3 thin films induced by switching the ferroelectric polarization of a top PbZr 0.2 Ti 0.8 O 3 layer. Anisotropic magnetoresistance (AMR) measurements were performed applying a magnetic field H in a plane perpendicular to the current density. By rotating H from the out-of-plane towards the in-plane direction, upon the ferroelectric polarization switching, a modulation of the normalized AMR amplitude was achieved. The dynamical electrostatic coupling at the interface of the two oxides is responsible for a reconstruction of the Mn 3de g orbitals which in turn affects the surface magnetic anisotropy of the magneto-electric system. The present work might have a broader impact, including in the field of multiferroic tunnel junctions, due to a better understanding of the coupling at the interface of the two ferroic oxides where the influence of the polarization on the magnetic degree of freedom is accomplished.

Ferroelectric capped magnetization in multiferroic PZT/LSMO tunnel junctions

“…A few XPS reports are also available in the literature on PZT/LSMO heterostructures; however, a thick layer of PZT restricts the investigation of chemical and valence states of layers close to interface. 17,18 Preziosi et al 10 have carefully demonstrated the transport properties of LSMO (5 nm) under two different polar states of PZT, which revealed that ferroelectric polarization significantly changes the interfacial magnetic anisotropy and affects the spin-orbit coupling. Leufke et al 11 have shown significant modification of magnetization of LSMO (7.…”

Giant Enhancement of Magnetic Anisotropy in Ultrathin Manganite Films via Nanoscale 1D Periodic Depth Modulation

“…Since the PHE signal in LSMO is orders of magnitude larger than that in ferromagnetic metals and not sensitive to the CMR background as the AMR [24][25][26], it is an ideal tool for high precision measurement of the magnetization orientation. All PHE measurements were taken at 100 K to achieve optimized signal [16,23,24].…”

“…For nanostructured samples with small dimensions, magnetization cannot be obtained from direct magnetometry measurements, but can be sensitively probed by magnetotransport techniques such as anisotropic magnetoresistance (AMR), PHE, and anomalous Hall effect [22][23][24][25][26][27]. The PHE is the sinusoidal dependence of the transverse (ρ xy ) resistivity on the angle between the in-plane magnetization and the current direction ( Fig.…”

Electric field modification of magnetotransport in Ni thin films on (011) PMN-PT piezosubstrates

“…2 There are numerous reports on voltage control of magnetization (see, e.g., reviews, 1-4 references therein, and recent Refs. 5 11), whereas for electric field effects on the anisotropic [12][13][14][15][16][17][18][19][20] and giant 13,21,22 [4][5][6][7][8][9][10][11]13,14,16,17,20 In such structures, upon application of an electric field, the piezoactive substrate induces a strain in the ferro(i)magnetic film and hence modifies its magnetic properties due to the magnetoelastic coupling effect. The (011) cut is particularly suitable because of the possibility of obtaining a high and well-defined uniaxial anisotropy by inducing simultaneously compressive and tensile strains in orthogonal [100] (x) and [011] (y) in-plane directions due to the different signs of d 31 and d 32 piezocoefficients.…”