We present results of electrical conduction studies of Ti/TiOx/Ti planar structures prepared by tip-induced local anodic oxidation (LAO) of titanium thin films. The prepared structures have shown almost linear I-V curves at temperatures between 300 K and 30 K, and only slight deviation from linear behaviour at lower temperatures. Electrical conductance of the structures can be adequately explained by a two-channel model where variable range hopping channels and metallic ones coexist in parallel, while a crossover from Mott to Efros-Shklovskii variable-range-hopping conductivity has been observed at decreasing temperature. The magnetoresistance of the studied structures is very small even in magnetic fields up to 9 T. The reported electrical properties of the structures indicate their promising applications as very low heat capacity temperature sensors for cryogenic region and high magnetic fields.
Electrical conduction through a two-terminal molecular device is studied using non-equilibrium Green's functions (NEGF) formalism. Such junction is made of a short linear wire which is connected to the metallic electrodes. Molecule itself is described with the help of Huckel (tight-binding) model with the electron interactions treated within extended Hubbard model (EHM), while the coupling to the electrodes is described with the help of a broad-band theory. Coulomb interactions within molecular wire are treated by means of the restricted Hartree-Fock (RHF) approximation. In particular, the inf…
We present an atomistic theory of electronic transport through single organic molecules that reproduces the important features of the current-voltage characteristics observed in recent experiments. We trace these features to their origin in the electronic structure of the molecules and their local atomic environment. We demonstrate how conduction channels arise from the molecular orbitals and elucidate which specific properties of the individual orbitals determine their contribution to the current.
Here we study incoherent transport through molecular wire treated as a linear chain of absorbers, where the phase-breaking processes are modeled by the use of imaginary point-like potentials. The calculations are performed within a transfer-matrix method of the scattering theory. An analytic expression for the transmission of a finite chain in obtained, while the electrical current is then computed with the help of the Tsu-Esaki formula. In particular, it is shown that the maximal current dependence on the wire length is exponential.
The observed temperature dependence of electrical conduction in polymer electrolytes is usually fitted with two separated equations: an Arrhenius equation at low temperatures and Vogel-Tamman-Fulcher (VTF) at high temperatures. We report here a derivation of a single equation to explain the variation of electrical conduction in polymer electrolytes at all temperature ranges. Our single equation is in agreement with the experimental data
The temperature dependence of the electrical transport of a individual tin oxide nanobelt was measured, in darkness, from 400 to 5K. We found four intrinsic electrical transport mechanisms through the nanobelt. It starts with Thermal-Activation Conduction between 400 and 314K, Nearest-Neighbor Hopping conduction between 268 and 115K, and Variable Range Hopping conduction below 58K, with a crossover from the 3D-Mott to the 3D-Efros-Shklovskii regime at 16K. We claim that this sequence reveal the three-dimensional nature of the electrical transport in the SnO2 nanobelts, even they are expected t…
The temperature dependent resistance $R$($T$) of polycrystalline ferromagnetic CoFeB thin films of varying thickness are analyzed considering various electrical scattering processes. We observe a resistance minimum in $R$($T$) curves below $\simeq$ 29 K, which can be explained as an effect of intergranular Coulomb interaction in a granular system. The structural and Coulomb interaction related scattering processes contribute more as the film thickness decreases implying the role of disorder and granularity. Although the magnetic contribution to the resistance is the weakest compared to these t…
In this work, the electrical properties of bilayer Antimonene with different stacking orders are studied. Density functional theory with van der Waals (vdW) correction is used to investigate the electrical performances. Two configurations demonstrate considerable bandgaps, whereas, the bandgaps are close to zero for other structures. The in-plane biaxial strain is applied to modify the electrical properties. The bandgap reaches a maximum at a specific strain level and then closes at more enormous compressive and tensile strains. The energy of three valleys ($Γ$, Q, and K) in the conduction ban…
In this work, the electrical and spin properties of monolayer MoSi2X4 (X= N, P, As, and Sb) under vertical strain are investigated. The band structures state that MoSi2N4 is an indirect semiconductor, whereas other compounds are direct semiconductors. The vertical strain has been selected to modify the electrical properties. The bandgap shows a maximum and decreases for both tensile and compressive strains. The valence band at K-point displays a large spin-splitting, whereas the conduction band has a negligible splitting. On the other hand, the second conduction band has a large spin-splitting…
Silver nanoparticles embedded in a dielectric matrix are investigated for their potential as broadband-absorbing optical sensor materials. This contribution focuses on the electrical properties of silver nanoparticles at various morphological stages. The electrical current through thin films, consisting of silver nanoparticles, was characterized as a function of film thickness. Three distinct conductivity zones were observed. Two relatively flat zones ("dielectric" for very thin films and "metallic" for films thicker than 300 - 400 Å) are separated by a sharp transition zone where percolation …
Silver nanowires have great application potential in fields like flexible electronic devices, solar cells and transparent electrodes. It is critical and fundamental to study the thermal and electrical transport properties in a single silver nanowire. In this work, the thermal and electrical transport in an individual silver nanowire is characterized down to 35 K with the steady state electro-thermal technique. The results indicate that, at room temperature, the electrical resistivity increases by around 4 folds compared from that of its bulk counterpart. After fitting the temperature dependent…
Anti-ThCr$_2$Si$_2$ type $RE_2$O$_2$Sb ($RE$ = rare earth) with Sb square net has shown insulating conduction so far. Here we report the synthesis of La$_2$O$_2$Sb epitaxial thin films for the first time by multilayer solid-phase epitaxy. The valence state of Sb was about -2 evaluated from X-ray photoemission spectroscopy measurement, and the indirect band gap of 0.17 eV was observed. The La$_2$O$_2$Sb epitaxial thin film showed unexpectedly high electrical conduction as a narrow gap semiconductor, whose resistivity at room temperature was approximately ten-thousand-fold lower than that of La$…
Measurements of the dc transport properties and the low-frequency conductivity noise in films of charge ordered Nd_0.5Ca_0.5MnO_3 grown on Si subtrate reveal the existence of a threshold field in the charge ordered regime beyond which strong non linear conduction sets in along with a large broad band conductivity noise. Threshold-dependent conduction disappears as T -> T_{CO}, the charge ordering temperature. This observation suggests that the charge ordered state gets depinned at the onset of the non-linear conduction.
Investigation of electrical conduction in polysilicon nanowires (polySiNW) with nanograins (5 to 20nm), based on Monte Carlo (MC) simulations and electrical measurements from 4K to 300K are presented. Some irregular Coulomb Oscillations (CO) are observed at temperatures lower than 200K showing several period widths due to the random distribution in grain size (5-20nm). A remarkable result consists in more effective oscillations observed at intermediate range of temperatures (between 25K and 150K) and high drain voltages. The temperature dependence of COs is explained by the fact that in a mult…
Controlled breakdown has recently emerged as a highly appealing technique to fabricate solid-state nanopores for a wide range of biosensing applications. This technique relies on applying an electric field of approximately 0.6-1 V/nm across the membrane to induce a current, and eventually, breakdown of the dielectric. However, a detailed description of how electrical conduction through the dielectric occurs during controlled breakdown has not yet been reported. Here, we study electrical conduction and nanopore formation in SiN$_x$ membranes during controlled breakdown. We show that depending o…
We find that the long-range magnetic ordering is absent and electrical conduction suppressed in Y$_{1.7}$Bi$_{0.3}$Ir$_2$O$_7$/YSZ(100) thin film prepared by pulsed laser deposition. The sharp down-turn of inverse magnetic susceptibility X-1(T) from the conventional Curie-Weiss behaviour below T* ~ 168K suggests an inhomogeneous ferromagnetic Griffiths like phase. The transport and magnetic properties are explained on the basis of the coexistence of mixed oxidation states of Ir, (i.e. Ir4+ and Ir3+) leading to non-magnetic defects and reduction in t2g density of states at the Fermi level.
We have investigated the electrical conduction processes in as-grown and thermally cycled ZnO single crystal as well as as-grown ZnO polycrystalline films over the wide temperature range 20--500 K. In the case of ZnO single crystal between 110 and 500 K, two types of thermal activation conduction processes are observed. This is explained in terms of the existence of both shallow donors and intermediately deep donors which are consecutively excited to the conduction band as the temperature increases. By measuring the resistivity $ρ(T)$ of a given single crystal after repeated thermal cycling in…
Current-voltage measurements have been made at room temperature on a Si-rich silicon oxide film deposited via Electron-Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD) and annealed at 750 - 1000$ ^\circ$C. The thickness of oxide between Si quantum dots embedded in the film increases with the increase of annealing temperature. This leads to the decrease of current density as the annealing temperature is increased. Assuming the Fowler-Nordheim tunneling mechanism in large electric fields, we obtain an effective barrier height $ϕ_{eff}$ of $\sim$ 0.7 $\pm$ 0.1 eV for an e…
Effects of x-ray irradiation on the crystal structure and the electrical resistance were examined at low temperatures for the insulating phase of spinel compound CuIr2S4. We found that the resistance decreases by more than five decades by irradiation at 8.5 K. The structural change from triclinic to tetragonal was observed at the same time. The x-ray-induced conductance is deduced to result from the destruction of Ir4+ dimers formed in the insulating phase. Slow relaxation of the resistance in the x-ray-induced state is also reported.
We determined the interface state density ($D_{\rm it}$) distributions in the vicinity of the conduction band edge in silicon carbide (SiC) metal-oxide-semiconductor (MOS) structures by reproducing the experimental current-voltage characteristics of MOS field effect transistors (MOSFETs) with numerical calculations. In the calculation, potential distributions and energy sub-bands in the inversion layer were calculated by solving Poisson and Schrödinger equations, respectively. We demonstrate that gate characteristics of the MOSFETs are well described by considering that the interface states ar…
The temperature and electrical field dependent conductivity of n-type CdSe nanocrystal thin films is investigated. In the low electrical field regime, the conductivity follows G ~ exp(-(T*/T)^0.5) in the temperature range 10K<T<120K. At high electrical field, the conductivity is strongly field dependent. At 4K, the conductance increases by eight orders of magnitude over one decade of bias. At very high field, conductivity is temperature-independent with G ~ exp(-(E*/E)^0.5). The complete behavior is very well described by variable range hopping with Coulomb gap.
Tin monosulfide (SnS) usually exhibits p-type conduction due to the low formation enthalpy of acceptor-type defects, and as a result n-type SnS thin films have never been obtained. This study realizes n-type conduction in SnS thin films for the first time by using RF-magnetron sputtering with Cl doping and sulfur plasma source during deposition. N-type SnS thin films are obtained at all the substrate temperatures employed in this study (221-341 C), exhibiting carrier concentrations and Hall mobilities of ~2 x 10 18 cm-3 and 0.1-1 cm V-1s-1, respectively. The films prepared without sulfur plasm…
Current-voltage characteristics of Au~/~YBa$_2$Cu$_3$O$_{7-δ}$ interfaces (Au/YBCO), built on optimally-doped YBCO thin films, grown by pulsed laser deposition, were measured as a function of temperature in the 50 K to 270 K range, for two different resistance states. A non-trivial equivalent circuit model is proposed, which reveals the existence of a highly inhomogeneous scenario composed by two complex layers: one presenting both a non-linear Poole-Frenkel conduction as well as Variable Range Hopping localization effects (probably associated with YBa$_2$Cu$_3$O$_{6}$) mixed with a minor meta…
Among the recent discoveries of domain wall functionalities, the observation of electrical conduction at ferroelectric domain walls in the multiferroic insulator BiFeO3 has opened exciting new possibilities. Here, we report evidence of electrical conduction also at 180° ferroelectric domain walls in the simpler tetragonal ferroelectric PZT thin films. The observed conduction shows nonlinear, asymmetric current-voltage characteristics, thermal activation at high temperatures and high stability. We relate this behavior to the microscopic structure of the domain walls, allowing local defects segr…
Germanium single crystal having 45 mm diameter and 100 mm length of 7N+ purity has been grown by Czochralski method. Structural quality of the crystal has been characterized by Laue diffraction. Electrical conduction and Hall measurements are carried out on samples retrieved from different parts of the crystal along the growth axis. Top part of the crystal exhibits lowest impurity concentration (~10^12/cm3) that gradually increases towards the bottom (10^13/cm3). The crystal is n-type at room temperature and the resistivity shows non-monotonic temperature dependence. There is a transition from…
We have studied the dark conductivity of a broad microstructural range of plasma deposited single phase undoped microcrystalline silicon films in a wide temperature range (15 - 450K) to identify the possible transport mechanisms and the interrelationship between film microstructure and electrical transport behavior. Different conduction behaviors seen in films with different microstructures are explained in the context of underlying transport mechanisms and microstructural features, for above and below room temperature measurements. Our microstructural studies have shown that different ranges …
We present evidence that electrical transport studies of epitaxial p-type GeMn thin films fabricated on high resistivity Ge substrates are severely influenced by parallel conduction through the substrate, related to the large intrinsic conductivity of Ge due to its small bandgap. Anomalous Hall measurements and large magneto resistance effects are completely understood by taking a dominating substrate contribution as well as the measurement geometry into account. It is shown that substrate conduction persists also for well conducting, degenerate, p-type thin films, giving rise to an effective …
We present electrical transport measurements of heterostructures comprised of BaTiO$_3$ and Ba$_{1-x}$Sr$_x$TiO$_3$ epitaxially grown on Ge. The Sr-alloying imparts compressive strain to the BaTiO$_3$, which enables the thermal expansion mismatch between BaTiO$_3$ and Ge to be overcome to achieve $c$-axis oriented growth. The conduction bands of BaTiO$_3$ and Ba$_{1-x}$Sr$_x$TiO$_3$ are nearly aligned with the conduction band of Ge, which facilitates electron transport. Electrical transport measurements through the dielectric stack exhibit rectifying behavior and hysteresis, where the latter i…
Olivine-type LiFePO$_{4}$ is widely considered as a candidate for Li-ion battery electrodes, yet its applicability in the pristine state is limited due to poor ionic and electronic conduction. Doping can be employed to enhance the material's electrical conductivity. However, this should be understood as incorporating electrically active impurities to manipulate the concentration of native point defects such as lithium vacancies and small hole polarons which are responsible for ionic and electronic conduction, respectively, and {\it not} as generating band-like carriers. Possible effects of mon…
Two-dimensional (2D) surface of the topological materials is an attractive channel for the electrical conduction reflecting the linearly-dispersive electronic bands. By applying a reliable systematic thickness t dependent measurement of sheet conductance, here we elucidate the dimensionality of the electrical conduction paths of a Weyl semimetal Co3Sn2S2. Under the ferromagnetic phase, the 2D conduction path clearly emerges in Co3Sn2S2 thin films, indicating a formation of the Fermi arcs projected from Weyl nodes. Comparison between 3D conductivity and 2D conductance provides the effective thi…
The structures, optical and electrical transport properties of SnO$_2$ films, fabricated by rf sputtering method at different oxygen partial pressures, were systematically investigated. It has been found that preferred growth orientation of SnO$_2$ film is strongly related to the oxygen partial pressure during deposition, which provides an effective way to tune the surface texture of SnO$_2$ film. All films reveal relatively high transparency in the visible range, and both the transmittance and optical band gap increase with increasing oxygen partial pressure. The temperature dependence of res…
High-quality, large-area epitaxial graphene can be grown on metal surfaces but its transport properties cannot be exploited because the electrical conduction is dominated by the substrate. Here we insulate epitaxial graphene on Ru(0001) by a step-wise intercalation of silicon and oxygen, and the eventual formation of a SiO$_2$ layer between the graphene and the metal. We follow the reaction steps by x-ray photoemission spectroscopy and demonstrate the electrical insulation using a nano-scale multipoint probe technique.
We study a scheme for electrical detection of the spin resonance (ESR) of a single electron trapped near a Field Effect Transistor (FET) conduction channel. In this scheme, the resonant Rabi oscillations of the trapped electron spin cause a modification of the average occupancy of a shallow trap, which can be detected through the change in the FET channel resistivity. We show that the dependence of the channel resistivity on the frequency of the rf field can have either peak or dip at the Larmor frequency of the electron spin in the trap.
The polarization of conduction electron spins due to an electrical current is observed in strained nonmagnetic semiconductors using static and time-resolved Faraday rotation. The density, lifetime, and orientation rate of the electrically-polarized spins are characterized by a combination of optical and electrical methods. In addition, the dynamics of the current-induced spins are investigated by utilizing electrical pulses generated from a photoconductive switch. These results demonstrate the possibility of a spin source for semiconductor spintronic devices without the use of magnetic materia…
Electrically steered conduction topologies and period-doubling phase dynamics in VO2
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所凝聚态物理国家实验室）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Laboratory for Ultrafast Transient Facility, Chongqing University（重庆大学超快瞬变设施实验室）；Hebei Key Laboratory of Photophysics Research and Application, Hebei Normal University（河北师范大学光物理研究与应用河北省重点实验室）；Songshan Lake Materials Laboratory（松山湖材料实验室）
We have conducted a careful study of current-voltage (I-V) characteristics in fully integrated commercial PbZr0.4Ti0.6O3 thin film capacitors with Pt bottom and Ir/IrO2 top electrodes. Highly reproducible steady state I-V were obtained at various temperatures over two decades in voltage from current-time data and analyzed in terms of several common transport models including space charge limited conduction, Schottky thermionic emission under full and partial depletion and Poole-Frenkel conduction, showing that the later is the most plausible leakage mechanism in these high quality films. In ad…
We investigate electrical conduction and breakdown behavior of 3D nano-carbon-stacked multilayer graphene (s-MLG) system with complete interlayer decoupling. The s-MLG is prepared by transferring and stacking large-area CVD-grown graphene monolayers, followed by wire patterning and plasma etching. Raman spectroscopy was used to confirm the layer number. The D-band peak indicates low defect level in the samples. Electrical current stressing induced doping is performed to shift the charge-neutrality Dirac point and decrease the graphene/metal contact resistance, improving the overall electrical …
Dielectric behavior and conductivity mechanism in lead-free (100-x)(Li0.12Na0.88)NbO3-xBaTiO3 (0 to x to 40) piezoelectric ceramics were investigated using impedance spectroscopy over a wide temperature (-100 oC to500 oC) and frequency range (0.1 Hz to1 MHz). The grain and grain boundary response as well as the relaxation processes at different frequencies and temperatures were also discussed. A low frequency dispersion in dielectric permittivity (LFDD), a typical characteristic of high-temperature behavior was observed both below and above the ferro-paraelectric phase transition temperature, …
High Frequency (GW) Post Processing of Transparent Conductive Oxide, ITO, leads to a significant improvement of Optical Transmission and Electrical Conduction. This is also true in case of ITO films in multilayered structures. The improvements happen without any affecting the lower layers (other layers of the multilayered Device). This Method is extremely selective and can process only the targeted film (layer).
NdFeO3 modified polycrystalline ceramics with composition (NdFeO3)0.1-(Ba0.7Sr0.3TiO3)0.9 (NFBST) ceramics have been synthesized via solid-state reaction route. The Rietveld refinement of the XRD data confirmed the existence of a tetragonal phase (P4mm) and a hexagonal phase (P63/mmc) in the prepared sample. The coexistence of phases has been also further confirmed from the Raman spectroscopy. The SEM image revealed dense microstructure with well packed grains of different sizes. At room temperature lossy P-E loop and weak ferromagnetism is observed in NFBST system. Complex impedance spectrosc…
The dependence of the electrical conductivity on the oxygen partial pressure is calculated for the prototypical perovskite $\Ba\TiØ_3$ based on data obtained from first-principles calculations within density functional theory. The equilibrium point defect concentrations are obtained via a self-consistent determination of the electron chemical potential. This allows to derive charge carrier concentrations for a given temperature and chemical environment and eventually the electrial conductivity. The calculations are in excellent agreement with experimental data if an accidental acceptor dopant …
Here we describe a new high frequency/high field continuous wave and pulsed electrically detected magnetic resonance (CW EDMR and pEDMR) setup, operating at 263 GHz and resonance fields between 0 and 12 T. Spin dependent transport in illuminated hydrogenated amorphous silicon p-i-n solar cells at 5 K and 90 K was studied by in operando 263 GHz CW and pEDMR alongside with complementary X-band CW EDMR. Benefiting from the superior resolution at 263 GHz, we were able to better resolve EDMR signals originating from spin dependent hopping and recombination processes. 5 K EDMR spectra were found to …
SmB6 is a strongly correlated mixed-valence Kondo insulator with a newly discovered surface state, proposed to be of non-trivial topological origin. However, the surface state dominates electrical conduction only below T* ~ 4 K limiting its scientific investigation and device application. Here, we report the enhancement of T * in SmB6 under the application of tensile strain. With 0.7% tensile strain we report surface dominated conduction at up to a temperature of 240 K, persisting even after the strain has been removed. This can be explained in the framework of strain-tuned temporal and spatia…
The electrical conductivity of the switching channel of vanadium dioxide thin-film sandwich structures is studied over a wide temperature range (15-300 K). It is shown that the electrical resistance of the channel varies with temperature as R~exp(aT-b/T) in the high-temperature region (above 70 K). The experimental results are discussed from the viewpoint of the small polaron hopping conduction theory which takes into account the influence of thermal lattice vibrations onto the resonance integral.
Thin films composed of Ge nanocrystals embedded in amorphous SiO2 matrix (Ge-NCs TFs) were prepared using a low temperature in-situ growth method. Unexpected high p-type conductivity was observed in the intrinsic Ge-NCs TFs. Unintentional doping from shallow dopants was excluded as a candidate mechanism of hole generation. Instead, the p-type characteristic was attributed to surface state induced hole accumulation in NCs, and the hole conduction was found to be a thermally activated process involving charge hopping from one NC to its nearest neighbor. Theoretical analysis has shown that the de…
We have investigated anisotropy in magnetic and electrical transport properties of Fe1-xCrxSb2 (0<= x <=1) single crystals. The magnetic ground state of the system evolves from paramagnetic to antiferromagnetic with gradual substitution of Fe with Cr. Anisotropy in electrical transport diminishes with increased Cr substitution and fades away by x=0.5. We find that the variable range hopping (VRH) conduction mechanism dominates at low temperatures for 0.4<= x <=0.75.
The intrinsic d.c. electrical resistivity ($ρ$) - measurable on single crystals only - is often the quantity first revealing the properties of a given material. In the case of CH$_3$NH$_3$PbI$_3$ perovskite measuring $ρ$ under white light illumination provides insight into the coexistence of extended and shallow localized states (0.1 eV below the conduction band). The former ones dominate the electrical conduction while the latter, coming from neutral defects, serve as a long-lifetime charge carrier reservoir accessible for charge transport by thermal excitation. Remarkably, in the best crysta…
Diffusive memristors continue to receive tremendous interest due to their ability to emulate biological neurons and thus aid the development of bio-inspired computation technology. A major issue with the diffusive memristor is the inability to reliably control the formation of the conduction filaments which affects both the device functionality and reproducibility of regimes after each application of voltage. Here we investigate the effect of gamma radiation on the electrical properties of the diffusive memristors based on metallic nanoparticles in dielectric matrix. Our experiments show that …
The author reports an experimental study of electrical and thermal transport in reduced graphene oxide (RGO)/polystyrene (PS) composites. The electrical conductivity ($σ$) of RGO/PS composites with different RGO concentrations at room temperature shows a percolation behavior with the percolation threshold of ~ 0.25 vol.%. Their temperature-dependent electrical conductivity follows Efros-Shklovskii (ES) variable range hopping (VRH) conduction in the temperature range of 30 to 300 K. The thermal conductivity ($κ$) of composites is enhanced by ~ 90 % as the concentration is increased from 0 to 10…
We have fabricated oxygen deficient polycrystalline ZnO films by the rf sputtering deposition method. To systematically investigate the charge transport mechanisms in these samples, the electrical resistivities have been measured over a wide range of temperature from 300 K down to liquid-helium temperatures. We found that below about 100 K, the variable-range-hopping (VRH) conduction processes govern the charge transport properties. In particular, the Mott VRH conduction process dominates at higher temperatures, while crossing over to the Efros-Shklovskii (ES) VRH conduction process at lower t…
Thin films prepared of semiconductor nanoparticles are promising for low-cost electronic applications such as transistors and solar cells. One hurdle for their breakthrough is their notoriously low conductivity. To address this, we precisely decorate CdSe nanoparticles with platinum domains of one to three nanometers in diameter by a facile and robust seeded growth method. We demonstrate the transition from semiconductor to metal dominated conduction in monolayered films. By adjusting the platinum content in such solution-processable hybrid, oligomeric nanoparticles the dark currents through d…
We report the nanoscale electrical imaging results in hexagonal $Lu_{0.6}Sc_{0.4}FeO_3$ single crystals using conductive atomic force microscopy (C-AFM) and scanning microwave impedance microscopy (MIM). While the dc and ac response of the ferroelectric domains can be explained by the surface band bending, the drastic enhancement of domain wall (DW) ac conductivity is clearly dominated by the dielectric loss due to DW vibration rather than mobile-carrier conduction. Our work provides a unified physical picture to describe the local conductivity of ferroelectric domains and domain walls, which …
