This phenomenon is related to the formation of defects in the microstructure of the insulator, which can be related to the movement of intrinsic species (i.e., oxygen ions in transition metal oxides [TMO]), or penetration of metallic ions from the electrodes into the insulator. [4] If the electrical Two-terminal metal/insulator/metal (MIM) memristors exhibiting threshold resistive switching (RS) can develop advanced key tasks in solid-state nano/ micro-electronic circuits, such as selectors and integrate-and-fire electronic neurons. MIM-like memristors using multilayer hexagonal boron nitride (h-BN) as dielectric are especially interesting because they have shown threshold RS with ultra-low energy consumption per state transition down to the zeptojoule regime. However, the factors enabling stable threshold RS at such low operation energies are still not fully understood. Here it is shown that the threshold RS in 150 nm × 150 nm Au/Ag/h-BN/Au memristors is especially stable because the temperature in the h-BN stack during operation (i.e., at low currents ≈1 μA) is very low (i.e., ≈310 K), due to the high in-plane thermal conductivity of h-BN and its low thickness. Only when the device is operated at higher currents (i.e., ≈200 μA) the temperatures at the h-BN increase remarkably (i.e., >500 K), which produce a stable non-volatile conductive nanofilament (CNF). This work can bring new insights to understand the performance of 2D materials based RS devices, and help to develop the integration of 2D materials in high-density nanoelectronics.
We study experimentally and numerically the dynamics of the spin ice material Dy 2 Ti 2 O 7 in the low temperature (T ) and moderate magnetic field (B) regime (T ∈ [0.1, 1.7] K, B ∈ [0, 0.3] T). Our objective is to understand the main physics shaping the out-of-equilibrium magnetisation vs. temperature curves in two different regimes. Very far from equilibrium, turning on the magnetic field after having cooled the system in zero field (ZFC) can increase the concentration of magnetic monopoles (localised thermal excitations present in these systems); this accelerates the dynamics. Similarly to electrolytes, this occurs through dissociation of bound monopole pairs. However, for spin ices the polarisation of the vacuum out of which the monopole pairs are created is a key factor shaping the magnetisation curves, with no analog. We observe a threshold field near 0.2 T for this fast dynamics to take place, linked to the maximum magnetic force between the attracting pairs. Surprisingly, within a regime of low temperatures and moderate fields, an extended Ohm's law can be used to describe the ZFC magnetisation curve obtained with the dipolar spinice model. However, in real samples the acceleration of the dynamics appears even sharper than in simulations, possibly due to the presence of avalanches. On the other hand, the effect of the field nearer equilibrium can be just the opposite to that at very low temperatures. Single crystals, as noted before for powders, abandon equilibrium at a blocking temperature T B which increases with field. Curiously, this behaviour is present in numerical simulations even within the nearest-neighbours interactions model. Simulations and experiments show that the increasing trend in T B is stronger
The authors report on the role of various reactive gases on the structure and properties of TiN thin films prepared by plasma enhanced atomic layer deposition (PEALD) from tetrakis(dimethylamido)titanium. The reactive gas plays an important role determining the film structure and properties. Nitrogen-based plasma (N2 and NH3) resulted in low oxygen (∼3%) and carbon (∼2%) contamination and well-defined columnar grain structure. A nitrogen excess (∼4%) was found in the films deposited using N2 plasma. The stoichiometric films and lowest resistivity (∼80 μΩ cm) were achieved using NH3 plasma. Deposition using H2 plasma resulted in higher carbon and oxygen contamination (∼6% for each element). The reactive gas also plays an important role in determining the grain size and preferential orientation. By varying the plasma chemistry, either (111) or (100) oriented films can be obtained. A mechanism determining the PEALD TiN preferential orientation is proposed. Finally, plasma induced degradation of the underlying dielectric layer is evaluated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.