Resistive switching devices are considered as one of the most promising candidates for next generation memories and nonvolatile logic applications. In this paper, BiFeO 3 :Ti/BiFeO (BFTO/BFO) bilayer structures with optimized BFTO/BFO thickness ratio which show symmetric, bipolar, resistive good retention endurance performance, presented. The mechanism is understood by a model flexible top bottom Schottky‐like barrier heights in structures. at both positive negative bias make it possible to...

Single-phase perovskite 5 at. % Mn-doped and undoped polycrystalline BaTiO3 thin films have been grown under different oxygen partial pressures by pulsed laser deposition on platinum-coated sapphire substrates. Ferroelectricity is only observed for the relatively high pressure. Compared to BaTiO3, reveals a low leakage current, increased dielectric loss, decreased constant. Ferromagnetism seen prepared pressure attributed formation of bound magnetic polarons (BMPs). This BMP enhanced...

Nonvolatile bipolar resistive switching has been observed in an Au/BiFeO3/Pt structure, where a Schottky contact and quasi-Ohmic were formed at the Au/BiFeO3 BiFeO3/Pt interface, respectively. By changing polarity of external voltage, is switched between two stable resistance states without electroforming process. The ratio larger than orders magnitude. understood by electric field - induced carriers trapping detrapping, which changes depletion layer thickness interface.

Pulsed laser deposited Au-BFO-Pt/Ti/Sapphire MIM structures offer excellent bipolar resistive switching performance, including electroforming free, long retention time at 358 K, and highly stable endurance. Here we develop a model on modifiable Schottky barrier heights elucidate the physical origin underlying in BiFeO3 memristors containing mobile oxygen vacancies. Increased speed is possible by applying large amplitude writing pulse as tunable both length of pulse. The local has been...

Memristive devices are popular among neuromorphic engineers for their ability to emulate forms of spike-driven synaptic plasticity by applying specific voltage and current waveforms at two terminals. In this paper, we investigate spike-timing dependent (STDP) with a single pairing one presynaptic spike post-synaptic in BiFeO3 memristive device. most materials the learning window is primarily function material characteristics not applied waveform. contrast, show that analog resistive...

Organic diodes consisting of molecular nano-pyramid structures sandwiched between metal and strained nano­membrane electrodes are created. The robust smooth contacts provided by self-curled layers render the nano-pyramids efficent channels for detecting nitrogen dioxide airflow.

Single-phase vanadium dioxide films grown on (0001) sapphire and (001) silicon substrates show a very different insulator–metal electronic transition. A detailed description of the growth mechanisms substrate–film interaction is given, characteristics transition are described by morphology grain boundary structure. (Tri-)epitaxy-stabilized columnar VO2 takes place substrate, whereas expected Zone II identified. We have found that in case Si substrate reasons for broader hysteresis lower...

This work reports the effect of Ti diffusion on bipolar resistive switching in Au/BiFeO3/Pt/Ti capacitor-like structures. Polycrystalline BiFeO3 thin films are deposited by pulsed laser deposition at different temperatures Pt/Ti/SiO2/Si substrates. From energy filtered transmission electron microscopy and Rutherford backscattering spectrometry it is observed that occurs if temperature above 600°C. The current-voltage (I-V) curves indicate can only be achieved structures where this occurs....

The dynamics of mobile oxygen vacancies depend on electric field and temperature, this is key to controlling interfacial resistive switching in BiFeO${}_{3}$ memristive devices, which are interesting especially for neuromorphic computing. authors use impedance spectroscopy quasistatic state measurements reveal the resistance changes such relate these redistribution via modeling. This work will also impact other oxides with similar devices.

Abstract BiFeO 3 based MIM structures with Ti-implanted Pt bottom electrodes and Au top have been fabricated on Sapphire substrates. The resulting metal-insulator-metal (MIM) show bipolar resistive switching without an electroforming process. It is evidenced that during the thin film growth Ti diffuses into layer. diffused effectively traps releases oxygen vacancies consequently stabilizes in structures. Therefore, using implantation of electrode, retention performance can be greatly...

We present a superconducting bolometer fabricated by rolled-up technology that allows one to combine the two-dimensionality (2D) of layer with helical spiral curvature. The is formed as free-standing Nb nanohelix acting an ultrathin transition-edge sensor (TES) and having negligible thermal contact substrate. demonstrate functionality thin-film TES examining its microwave-detection performance in comparison commercial cryogenic from QMC Instruments. has been revealed feature noise equivalent...

Abstract A novel small signal equivalent circuit model is proposed in the inversion regime of metal/( ZnO , ZnMnO and ZnCoO ) semiconductor/ Si 3 N 4 insulator/p-Si semiconductor (MSIS) structures to describe distinctive nonlinear frequency dependent capacitance ( C-F conductance G-F behaviour range from 50 Hz 1 MHz. We modelled fully depleted thin films extract static dielectric constant ε r . The extracted enhancement magnetic n-type conducting ≥ 13.0) 25.8) comparison unmagnetic =...

Emerging brain-inspired neuromorphic computing paradigms require devices that can emulate the complete functionality of biological synapses upon different neuronal activities in order to process big data flows an efficient and cognitive manner while being robust against any noisy input. The memristive device has been proposed as a promising candidate for emulating artificial due their complex multilevel dynamical plastic behaviors. In this work, we exploit ultrastable analog BiFeO 3...

BiFeO 3 thin films were grown on Pt/c-sapphire substrates by pulsed laser deposition with different growth rates. With increasing rate the leakage current is decreased and conduction mechanism changes from bulk-limited Poole–Frenkel emission to interface-limited Schottky emission. In present letter, we show that only of BiFeO3 close metal contacts has be increased in order reduce observe saturated polarization-electric field hysteresis loops.

Polycrystalline, hexagonal HoMnO3 thin films sandwiched between an un-patterned Pt/Ti bottom electrode and a circularly patterned Al top reveal forming-free, polarity dependent predictable random, unipolar resistive switching with stable retention, resistance ratio high state (HRS) low (LRS) larger than 104. An equivalent circuit model is proposed to describe the memristor as three-layered capacitor structure. Based on energy band diagram of structure under applied negative positive write...

Low-energy <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{Ar}^{+}$</tex></formula> ion irradiation has been applied to an Au/ Notation="TeX">$\hbox{BiFeO}_{3}$</tex></formula> /Pt capacitor structure before deposition of the Au top electrode. The irradiated thin film exhibits multilevel resistive switching (RS) without detrimental resistance degradation, which makes intermediate states more...

We report a unipolar, nonvolatile resistive switching in polycrystalline YMnO3 thin films grown by pulsed laser deposition and sandwiched between Au top Ti/Pt bottom electrodes. The ratio of the resistance OFF ON state is larger than 103. observed phenomena can be attributed to formation rupture conductive filaments within multiferroic film. generation paths under applied electric field discussed terms presence grain boundaries charged domain walls inherently formed hexagonal YMnO3. Our...

In this experimental and theoretical work we focus on the technique of pulsed laser annealing applied to metastable ferromagnetic semiconductor GaMnAs. Analytical heat-flow calculations are used illustrate position time-dependent temperature distribution during whole process. Such will also play an indispensable role for preparation other new diluted semiconductors by ion implantation subsequent annealing. The structural, magnetic, magnetotransport properties GaMnAs have been probed in...

Resistively switching oxides are promising materials for use in electronic applications such as nonvolatile memories, logic gates, and artificial synapses. This work presents the bipolar resistive (BRS) YMnO3/Nb:SrTiO3 pn-heterojunctions. A thermally driven electroforming process is required prior to observed BRS. Results indicate that BRS originates from combined effects of charge trapping detrapping processes along with electro-migration charged point defects depletion layer...

BiFeO3 thin films have been grown on Pt/Ti/SiO2/Si substrates with pulsed laser deposition using Au as the top electrode. The resistive switching property of Au/BiFeO3/Pt stack has significantly improved by carefully tuning oxygen pressure during growth, and a large ratio ~4500 achieved. modifies concentration vacancies rectifying behavior Au/BiFeO3 junction, consequently influences whole stack. takes place homogeneously over entire electrode, shows long-term retention.

We report the fabrication of Ge:Mn ferromagnetic semiconductors by Mn-ion implantation into Ge followed pulsed laser annealing. Benefiting from short time annealing, hole concentration in Mn-implanted has been increased two orders magnitude 10$^{18}$ to over 10$^{20}$ cm$^{-3}$. Likely due high concentration, we observe that longitudinal and Hall resistances exhibit same hysteresis as magnetization, which is usually considered a sign carrier-mediated ferromagnetism.

BiFeO3 thin films have been deposited on Pt/sapphire and Pt/Ti/SiO2/Si substrates with pulsed laser deposition using the same growth conditions. Au was sputtered as top electrode. The microscopic structure of film varies by changing underlying substrate. Thin are not resistively switchable due to formation Schottky contacts at both bottom interfaces. However, exhibit an obvious resistive switching behavior under forward bias. conduction mechanisms in discussed understand different behaviors.

A capacitive switching behavior is observed in a Si 3 N 4 /p‐Si‐based metal–insulator–semiconductor (MIS) structure due to the electron tunneling at /p‐Si interface. BiFeO (BFO) layer deposited on by pulsed laser deposition technique obtain memcapacitive effect as distribution of positive charges can be stabilized polarization charge ferroelectric BFO coating layer. The Al/BFO/Si /p‐Si/Au MIS also sensitive both intensity and wavelength illumination, which offers possibility create...