Hybrid supercapacitors for reversible control of magnetism

Molinari, Alan; Leufke, Philipp M.; Reitz, Christian; Dasgupta, Subho; Witte, Ralf; Kruk, Robert; Hahn, Horst

doi:10.1038/ncomms15339

Cited by 60 publications

(49 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The growth of LSMO on STO (001) was found to be epitaxial, in agreement with previous reports [11,29]. The epitaxial nature of the LSMO films was found to be maintained after fluorination, confirming that the chosen fluorination conditions are suitable to avoid decomposition into lanthanum oxide fluoride or strontium fluoride, which are well-known decomposition products of metastable oxyfluorides [30].…”

Section: Resultssupporting

confidence: 89%

Anion Doping of Ferromagnetic Thin Films of La0.74Sr0.26MnO3−δ via Topochemical Fluorination

et al. 2018

Self Cite

View full text Add to dashboard Cite

Chemical doping via insertion of ions into the lattice of a host material is a key strategy to flexibly manipulate functionalities of materials. In this work, we present a novel case study on the topotactic insertion of fluoride ions into oxygen-deficient ferromagnetic thin films of La0.74Sr0.26MnO3−δ (LSMO) epitaxially grown onto single-crystal SrTiO3 (STO) substrates. The effect of fluorination on the film structure, composition, and magnetic properties is compared with the case of oxygen-deficient and fully-oxidized LSMO films. Although incorporation of F− anions does not significantly alter the volume of the LSMO unit cell, a strong impact on the magnetic characteristics, including a remarkable suppression of Curie temperature and saturation magnetization accompanied by an increase in magnetic coercivity, was found. The change in magnetic properties can be ascribed to the disruption of the ferromagnetic exchange interactions along Mn-anion-Mn chains driven by F− doping into the LSMO lattice. Our results indicate that F− doping is a powerful means to effectively modify the magnetic functional properties of perovskite manganites.

show abstract

Section: Resultssupporting

confidence: 89%

Anion Doping of Ferromagnetic Thin Films of La0.74Sr0.26MnO3−δ via Topochemical Fluorination

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…[49,[79][80][81][82] In this Adv. [49,120,121] Caution should be taken when the voltage is not swept quasi-continuously, but is kept fixed for a prolonged period of time (several minutes). 2019, 31, 1806662 Figure 3.…”

Section: Me Coupling Via Charge Carrier Dopingmentioning

confidence: 96%

“…This is made possible by the very nature of electrolyte gating: upon application of an external voltage a thin layer of electrolyte counterions is electrostatically physisorbed onto the electrode surface and effectively screens the charge accumulated in the electrode within a short distance of ≈1 nm. [49] Notably, pseudocapacitors are of potential interest for investigation of ME effect, because several of them incorporate 3d transition metals, whose presence is a prerequisite for magnetism to occur. [117] Apart from electrostatic doping via EDL charging, the situation is somewhat more complicated in solid/liquid devices, since an additional mechanism of charge accumulation may be occurring.…”

Section: Me Coupling Via Charge Carrier Dopingmentioning

confidence: 99%

“…Charge doping is a surface or near-surface effect, ionic migration can extend deeper into the bulk, whereas strain intervenes on a broader macroscopic scale. [49,[79][80][81][82] In this respect, the physicochemical nature of the ME interface plays a key role in determining the response of a magnetic material upon application of an external electrical stimulus. In particular, distinguishing between electrostatic and electrochemical effects is a hotly debated topic in the literature.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, concerning device fabrication, liquid gating methods permit to cover large surface area samples regardless of their morphology, such as thin films, [49] nanoparticles, [50] and porous materials, [91] by simply pouring the desired amount of electrolyte onto the specimen. For instance, concerning device fabrication, liquid gating methods permit to cover large surface area samples regardless of their morphology, such as thin films, [49] nanoparticles, [50] and porous materials, [91] by simply pouring the desired amount of electrolyte onto the specimen.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Voltage‐Control of Magnetism in All‐Solid‐State and Solid/Liquid Magnetoelectric Composites

2019

Self Cite

View full text Add to dashboard Cite

activities. [1][2][3][4][5][6][7][8][9][10][11][12] From a technological perspective, several low-power ME applications have been envisioned, comprising devices for memory storage and processing, [13,14] tuning and filtering of RF/microwave signals, [15,16] energy conversion and harvesting, [17,18] sensing, [19,20] and actuation. [21,22] By definition, the direct ME effect is manifested when an electric polarization P is induced by usage of a magnetic field H in accordance with Δ Δ to compare the strength of the interaction between electricity and magnetism among different magnetoelectric systems. chemical control of the physical (magnetic) properties in metals and oxide nanostructures; electrostatic doping via field-effect; reversible magnetic phase transitions induced with ionic liquid charging; spintronics; printed electronics; fabrication of solution-processed devices (transistors, etc.)There are some nontrivial reasons explaining why solid/ liquid ME composites developed later than all-solid-state approaches. From an experimental perspective, the usage of conventional aqueous electrolytes poses some restrictions in terms of the operating conditions. Concerning the applied voltage, water electrolysis already occurs at a low voltage of

show abstract

Voltage‐Controlled On/Off Switching of Ferromagnetism in Manganite Supercapacitors

2017

Self Cite

View full text Add to dashboard Cite

liquid devices via surface electrostatic doping [20][21][22][23] (as in electric doublelayer (EDL) capacitors) or via bulk ionic migration [12,[15][16][17][18][19] (akin to electrochemical batteries). Recently, robust ME effect was achieved in magnetic supercapacitors [24,25] via a surface electrochemical mechanism called pseudocapacitance. [26,27] By making use of interfacial redox reactions, pseudocapacitors concurrently benefit of fast, reversible charging/discharging processes (typical of EDL capacitors) and high amounts of stored charge (typical of electrochemical batteries).From a technological perspective, the idea of controlling magnetic phase transitions in a supercapacitor where the magnetic counterpart is composed of a manganese-based oxide is very appealing. Indeed, several manganites [28] exhibit ferromagnetism and high degree of spin polarization intrinsically coupled to each other in proximity of room temperature. Thus, a low-power electric field could enable the simultaneous switching of magnetic and spintronic degrees of freedom without losing reversibility and switching speed.In this work, we selected, as a model system, a magnetic manganite supercapacitor made of an ultrathin film of La 0.74 Sr 0.26 MnO 3 (LSMO) charged with an ionic liquid electrolyte (DEME + -TFSI − ). By exploiting surface capacitive and pseudocapacitive charging mechanisms, we demonstrate the repetitive and complete suppression and recovery of ferromagnetism in LSMO at low-energy cost and remarkable switching speed in the 200-250 K temperature range.Atomically smooth LSMO films (see Figure 1a) with an optimized thickness of ≈3 nm and a surface area of ≈0.4 cm 2 were epitaxially grown on (001)-oriented SrTiO 3 (STO) substrates by magnetron sputtering. For a film thickness of ≈3 nm, a good compromise has been reached to maintain a high surfaceto-volume ratio and to preserve the Curie temperature of LSMO above the freezing point of the ionic liquid.In order to quantitatively track the LSMO magnetization while charging its surface with an ionic liquid, superconducting quantum interference device (SQUID) magnetometry and cyclic voltammetry (CV) measurements were combined and synchronized in situ (see the Experimental Section). The solid/ liquid devices consisted of a ME tuning cell with a configuration similar to an electrolytic capacitor (see sketch in Figure 1b).By application of a positive (negative) external voltage, the TFSI − (DEME + ) ions accumulate onto the surface of LSMO The ever-growing technological demand for more advanced microelectronic and spintronic devices keeps catalyzing the idea of controlling magnetism with an electric field. Although voltage-driven on/off switching of magnetization is already established in some magnetoelectric (ME) systems, often the coupling between magnetic and electric order parameters lacks an adequate reversibility, energy efficiency, working temperature, or switching speed. Here, the ME performance of a manganite supercapacitor composed of a ferromagnetic, spin-polarized ultrathin...

show abstract

Hybrid supercapacitors for reversible control of magnetism

Cited by 60 publications

References 49 publications

Anion Doping of Ferromagnetic Thin Films of La0.74Sr0.26MnO3−δ via Topochemical Fluorination

Anion Doping of Ferromagnetic Thin Films of La0.74Sr0.26MnO3−δ via Topochemical Fluorination

Voltage‐Control of Magnetism in All‐Solid‐State and Solid/Liquid Magnetoelectric Composites

Voltage‐Controlled On/Off Switching of Ferromagnetism in Manganite Supercapacitors

Contact Info

Product

Resources

About