scholarly journals Local Electric Property Modification of Ferroelectric Tunnel Junctions Induced by Variation of Polarization Charge Screening Conditions under Measurement with Scanning Probe Techniques

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3323
Author(s):  
Natalia Andreeva ◽  
Anatoliy Petukhov ◽  
Oleg Vilkov ◽  
Adrian Petraru ◽  
Victor Luchinin
Keyword(s):  
Tunnel Junctions ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Tunnel Barrier ◽  
Ambient Conditions ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Difference

Scanning tunneling spectroscopy in ultrahigh vacuum conditions and conductive atomic-force microscopy in ambient conditions were used to study local electroresistive properties of ferroelectric tunnel junctions SrTiO3/La0.7Sr0.3MnO3/BaTiO3. Interestingly, experimental current-voltage characteristics appear to strongly depend on the measurement technique applied. It was found that screening conditions of the polarization charges at the interface with a top electrode differ for two scanning probe techniques. As a result, asymmetry of the tunnel barrier height for the opposite ferroelectric polarization orientations may be influenced by the method applied to study the local tunnel electroresistance. Our observations are well described by the theory of electroresistance in ferroelectric tunnel junctions. Based on this, we reveal the main factors that influence the polarization-driven local resistive properties of the device under study. Additionally, we propose an approach to enhance asymmetry of ferroelectric tunnel junctions during measurement. While keeping the high locality of scanning probe techniques, it helps to increase the difference in the value of tunnel electroresistance for the opposite polarization orientations.

scholarly journals Electronic Structure of Oxygen-Deficient SrTiO3 and Sr2TiO4

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 580 ◽  
Author(s):  
Ali Al-Zubi ◽  
Gustav Bihlmayer ◽  
Stefan Blügel
Keyword(s):  
Density Functional ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
The Core ◽  
Atomic Force ◽  
Level Shifts ◽  
Spectroscopic Signatures ◽  
Gap States

The conductive behavior of the perovskite SrTiO 3 is strongly influenced by the presence of oxygen vacancies in this material, therefore the identification of such defects with spectroscopic methods is of high importance. We use density functional theory to characterize the defect-induced states in SrTiO 3 and Sr 2 TiO 4 . Their signatures at the surface, the visibility for scanning tunneling spectroscopy and locally conductive atomic force microscopy, and the core-level shifts observed on Ti atoms in the vicinity of the defect are studied. In particular, we find that the exact location of the defect state (e.g., in SrO or TiO 2 planes relative to the surface) are decisive for their visibility for scanning-probe methods. Moreover, the usual distinction between Ti 3 + and Ti 2 + species, which can occur near defects or their aggregates, cannot be directly translated in characteristic shifts of the core levels. The width of the defect-induced in-gap states is found to depend critically on the arrangement of the defects. This also has consequences for the spectroscopic signatures observed in so-called resistive switching phenomena.

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

SCANNING PROBE MICROSCOPY BASED NANOSCALE PATTERNING AND FABRICATION

COSMOS ◽  
2007 ◽  
Vol 03 (01) ◽  
pp. 1-21 ◽  
Author(s):  
XIAN NING XIE ◽  
HONG JING CHUNG ◽  
ANDREW THYE SHEN WEE
Keyword(s):  
Integrated Circuits ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Nanoscale Patterning ◽  
Atomic Force ◽  
Probe Microscope ◽  
Molecular Manipulation

Nanotechnology is vital to the fabrication of integrated circuits, memory devices, display units, biochips and biosensors. Scanning probe microscope (SPM) has emerged to be a unique tool for materials structuring and patterning with atomic and molecular resolution. SPM includes scanning tunneling microscopy (STM) and atomic force microscopy (AFM). In this chapter, we selectively discuss the atomic and molecular manipulation capabilities of STM nanolithography. As for AFM nanolithography, we focus on those nanopatterning techniques involving water and/or air when operated in ambient. The typical methods, mechanisms and applications of selected SPM nanolithographic techniques in nanoscale structuring and fabrication are reviewed.

Measurement of Plasticity Gradients with Scanning Probe Microscopy

1993 ◽  
Vol 318 ◽  
Author(s):  
James D. Kiely ◽  
Dawn A. Bonnell
Keyword(s):  
Fracture Surface ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Ceramic System ◽  
Force Microscopy ◽  
Metal Fracture ◽  
Atomic Force ◽  
Metal Ceramic

ABSTRACTScanning Tunneling and Atomic Force Microscopy were used to characterize the topography of fractured Au /sapphire interfaces. Variance analysis which quantifies surface morphology was developed and applied to the characterization of the metal fracture surface of the metal/ceramic system. Fracture surface features related to plasticity were quantified and correlated to the fracture energy and energy release rate.

scholarly journals Structure-resistive property relationships in thin ferroelectric BaTiO$$_{3}$$ films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
N. V. Andreeva ◽  
A. Petraru ◽  
O. Yu. Vilkov ◽  
A. E. Petukhov
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Point Defects ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Ferroelectric Films ◽  
Force Microscopy ◽  
Atomic Force

Abstract A combined study of local structural, electric and ferroelectric properties of SrTiO$$_{3}$$ 3 /La$$_{0.7}$$ 0.7 Sr$$_{0.3}$$ 0.3 MnO$$_{3}$$ 3 /BaTiO$$_{3}$$ 3 heterostructures was performed by Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy in the temperature range 30–295 K. The direct correlation of film structure (epitaxial, nanocrystalline or polycrystalline) with local electric and ferroelectric properties was observed. For polycrystalline ferroelectric films the predominant polarization state is defined by the peculiarity of screening the built-in field by positively charged point defects. Based on Scanning Tunneling Spectroscopy results, it was found that a sequent voltage application provokes the modification of local resistive properties related to the redistribution of point defects in thin ferroelectric films. A qualitative analysis of acquired Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy images together with Scanning Tunneling Spectroscopy measurements enabled us to conclude that in the presence of structural defects the competing processes of electron injection, trap filling and the drift of positively charged point defects drives the change of resistive properties of thin films under applied electric field. In this paper, we propose a new approach based on Scanning Tunneling Microscopy/Spectroscopy under ultrahigh vacuum conditions to clarify the influence of point defects on local resistive properties of nanometer-thick ferroelectric films.

AFM Study of Untreated and Treated Fibers of Mongolian Goat Cashmere

2009 ◽  
Vol 610-613 ◽  
pp. 175-178 ◽  
Author(s):  
Namsrai Javkhlantugs ◽  
Enkhbaatar Ankhbayar ◽  
Khishigjargal Tegshjargal ◽  
Damdin Enkhjargal ◽  
Chimed Ganzorig
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Fine Structure ◽  
Ambient Conditions ◽  
Bleaching Process ◽  
Surface Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
The Difference

The morphological surface change of untreated and treated fibers of the Mongolian goat cashmere was investigated by atomic force microscopy (AFM) at ambient conditions. The cuticle scale heights of the Mongolian goat cashmere fibers were measured by the AFM for the fibers before and after treatment. The experimental results showed that the difference between the fine structure of the cuticle and surface roughness of untreated and treated fibers. We found that the surface morphological change of the cashmere fibers was strongly degraded after the bleaching process.

scholarly journals Исследование пленок диметилдиимида перилентетракарбоновой кислоты методами циклической термодесорбции и сканирующей зондовой микроскопии

2018 ◽  
Vol 60 (2) ◽  
pp. 255
Author(s):  
А.Е. Почтенный ◽  
А.Н. Лаппо ◽  
И.П. Ильюшонок
Keyword(s):  
Atomic Force Microscopy ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Bandgap Width ◽  
Kelvin Probe ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Probe Spectroscopy

AbstractSome results of studying the direct-current (DC) conductivity of perylenetetracarboxylic acid dimethylimide films by cyclic oxygen thermal desorption are presented. The microscopic parameters of hopping electron transport over localized impurity and intrinsic states were determined. The bandgap width and the sign of major current carriers were determined by scanning probe microscopy methods (atomic force microscopy, scanning probe spectroscopy, and photoassisted Kelvin probe force microscopy). The possibility of the application of photoassisted scanning tunneling microscopy for the nanoscale phase analysis of photoconductive films is discussed.

COMPARATIVE STUDY OF THIOL FILMS ON C(0001) AND Au(111) SURFACES BY SCANNING PROBE MICROSCOPY

1997 ◽  
Vol 04 (04) ◽  
pp. 637-649 ◽  
Author(s):  
F. TERÁN ARCE ◽  
M. E. VELA ◽  
R. C. SALVAREZZA ◽  
A. J. ARVIA
Keyword(s):  
Pyrolytic Graphite ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Electrochemical Characteristics ◽  
Tunneling Microscopy ◽  
Test Reaction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Electron Transfer Processes ◽  
Substrate Nature

The structures resulting from 1-dodecanethiol, 1-butanethiol and 1,9-nonanedithiol films produced on highly oriented pyrolytic graphite (HOPG) and gold(111) have been comparatively studied by scanning probe microscopies. Molecular resolution images resulting from atomic force microscopy (AFM) and scanning tunneling microscopy (STM) of different thiol films show the formation of arrays of molecules parallel to the HOPG surface. The electrochemical response of the ferro-ferricyanide reaction was used to test the characteristics of electron transfer processes in thiol-covered HOPG as compared to the bare substrate. The decrease in the heterogeneous rate constant for the test reaction appears to be directly related to the degree of film thickness uniformity. For comparison, films with the same kind of thiols were produced on Au(111). Although the electrochemical characteristics of these films appear to be the same irrespective of the substrate nature, the structure of the films on Au(111) is different from that produced on HOPG.

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