Semiconductor/Piezoelectrics Hybrid Heterostructures with Highly Effective Gate-Tunable Electrotransport and Magnetic Behaviors

Abstract

We report the epitaxial growth of oxygen deficient titanium dioxide thin films on 0.7Pb(MgNb)O-0.3PbTiO (PMN-PT) single crystals and realized highly effective in situ electrostatic manipulation of electrotransport and magnetism of TiO films via gate voltages. Upon the polarization switching in the PMN-PT, the carrier density of the TiO film could be reversibly modified, resulting in a large nonvolatile resistivity modulation by ∼51% at T = 300 K, approximately 4-12 times larger than that of other transition-metal oxide film/PMN-PT structures. By taking advantage of in situ manipulation of the carrier density via gate voltages, we found that competition between the trap of electrons by the Ti-V pairs and that by the positive polarization charges at the interface results in a significant resistivity relaxation upon the polarization switching, and revealed that magnetization is inversely correlated with the carrier density of the TiO film. Such hybrid structures combining materials with dissimilar functionalities may have potential applications in multifunctional devices which can take advantage of the useful and unique properties of both materials.

Reversible and nonvolatile manipulation of the electronic transport properties of topological insulators by ferroelectric polarization switching

“…Due to the nonvolatile nature of polarization charges at the interface, 35,36 the resistance for the P þ r and P À r states exhibits distinct differences down to the lowest temperature for all CBS films with different thicknesses ( Fig. 1g and Supplementary Figure S4A).…”

“…Indeed, n was modified by ∼46% at 2 K and by ∼23% at 300 K as the polarization is switched from P þ r to P À r , while the electron mobility μ is only weakly modified by the polarization switching (Supplementary Figure S4B). For the present PMN-PT with a rhombohedral crystal structure the polarization switching from P þ r (i.e., the [111] direction) to P À r (i.e., the [-1-1-1] direction), as schematically illustrated in Figure S5 (Supplementary Materials), should not induce any lattice strain, 35,36 which is confirmed by the X-ray diffraction results shown in Figure S6 (Supplementary Materials), where the PMN-PT(111) and CBS(0003), (0006), (00015) diffraction peaks remain unchanged as the polarization state was switched from P þ r to P À r . Further, PFM measurements show that the polarization direction had been fully and reversibly switched between the [111] and the [-1-1-1] directions by electric voltages, as evidenced by the uniform and sharp contrast between the two domain states within the dotted blue boxes (Fig.…”

Room‐Temperature Reversible and Nonvolatile Tunability of Electrical Properties of Cr‐Doped In2O3 Semiconductor Thin Films Gated by Ferroelectric Single Crystal and Ionic Liquid

“…Here, , where and are the resistivity of ICO011 films for theand states, respectively. The Δρ/ρ value is ≈150–17 000 times larger than those reported previously for thin film/PMN‐ x PT heterostructures . Considering practical applications, the reproducibility and stability of the resistivity states of the heterostructures are crucial.…”

“…Among all ferroelectrics reported so far, (1− x )PbMg 1/3 Nb 2/3 O 3 – x PbTiO 3 (PMN‐ x PT) single crystals are greatly favored by researchers because of their ultrahigh piezoelectric coefficient ( d 33 ≈ 2000 pC N −1 ), superior ferroelectric polarization ( P r ≈ 30–40 µC cm −2 ), ultralow leakage current (<6 nA cm −2 ), and large electromechanical coupling coefficient ( k 33 ≈ 0.9) near the morphotropic phase boundary (0.29 ≤ x ≤ 0.33) . As of now, multiple types of thin films such as vanadium dioxides, manganites, ferrites, ferromagnetic metals and alloys, semiconductors, photoluminescent oxides, and superconductors have been grown on polished PMN‐ x PT single‐crystal substrates. For all reported thin film/PMN‐ x PT heterostructures, two major effects (i.e., the lattice strain effect and the ferroelectric field effect) occur at interfacial region upon the application of electric fields to PMN‐ x PT.…”

Interfacial Effect Enhanced Electric Field Control of the Magnetism in Pt/Fe/PMN-PT Heterostructures

“…Meanwhile, the charge mediated ME coupling effect offers a promising way to tune the ME coupling effect. Previous literatures are focus on the magnetic reconstitution, magnetic moment, and anisotropy. − The magnetization variation in the diluted magnetic semiconductor/PMN-PT heterostructures is closely related to the carrier density change under the electric field. , Strain and charge comediated ME coupling effects are also demonstrated in the ferromagnetic metal and oxides deposited on the PMN-PT substrate. , However, reports about the charge mediated ME coupling effect are limited, and the mechanism is also explained in phenomenology. , …”