Dislocation nucleation on a near surface void leading to surface protrusion growth under an external electric field

2013 ◽  
Vol 114 (3) ◽  
pp. 033519 ◽  
Author(s):  
A. S. Pohjonen ◽  
S. Parviainen ◽  
T. Muranaka ◽  
F. Djurabekova
2012 ◽  
Vol 225 ◽  
pp. 727-731 ◽  
Author(s):  
T. Frömling ◽  
H. Hutter ◽  
C. Leach ◽  
N.K. Ali ◽  
K. Reichmann ◽  
...  

2014 ◽  
Vol 70 (a1) ◽  
pp. C233-C233
Author(s):  
Juliane Hanzig ◽  
Matthias Zschornak ◽  
Erik Mehner ◽  
Florian Hanzig ◽  
Sven Jachalke ◽  
...  

Stoichiometric perovskite-type strontium titanate acts as an insulator because of its wide electronic band gap and has therefore great potential as high-k dielectric and storage material in memory applications. Degradation phenomena of insulating properties of transition metal oxides occur during long time voltage application. From the defect chemistry point of view the question arises how mobile species react on an external electric field and which impact the redistribution has on the stability of the crystal structure. Here, we discuss near-surface reversible structural changes in SrTiO3 single crystals caused by oxygen vacancy redistribution in an external electric field. We present in-situ X-ray diffraction during and after electroformation. Several reflections are monitored and show a tetragonal elongation of the cubic unit cell. Raman investigations were carried out to verify that the expansion involves a transition from the centrosymmetric to a less symmetric structure. Regarding a whole formation cycle, two different time scales occur: a slow one during the increase of the lattice constant and a fast one after switching off the electric field. Based on the experimental data we suggest a model containing the formation of a polar SrTiO3 unit cell stabilized by the electric field, which is referred to as migration-induced field-stabilized polar phase [1] at room temperature. As expected by a non-centrosymmetric crystal structure, pyroelectric properties will be presented in conjunction with temperature modulated electroformation cycles. Furthermore, we show that intrinsic defect separation establishes a non-equilibrium accompanied by an electromotive force. A comprehensive thermodynamic deduction in terms of theoretical energy and entropy calculations indicates an exergonic electrochemical reaction after the electric field is switched off. Based on that driving force the experimental and theoretical proof of concept of a solid-state SrTiO3 battery is reported.


2020 ◽  
Vol 62 (12) ◽  
pp. 2384-2392 ◽  
Author(s):  
A. G. Kulikov ◽  
A. E. Blagov ◽  
N. V. Marchenkov ◽  
Yu. V. Pisarevskii ◽  
M. V. Kovalchuk

JETP Letters ◽  
2018 ◽  
Vol 107 (10) ◽  
pp. 646-650 ◽  
Author(s):  
A. G. Kulikov ◽  
A. E. Blagov ◽  
N. V. Marchenkov ◽  
V. A. Lomonov ◽  
A. V. Vinogradov ◽  
...  

2018 ◽  
Vol 189 (02) ◽  
pp. 187-194 ◽  
Author(s):  
Nikita V. Marchenkov ◽  
Anton G. Kulikov ◽  
Ivan I. Atknin ◽  
Arsen A. Petrenko ◽  
Alexander E. Blagov ◽  
...  

2017 ◽  
Vol 9 (3) ◽  
pp. 03044-1-03044-3
Author(s):  
M. B. Belonenko ◽  
◽  
N. N. Konobeeva ◽  

2019 ◽  
Vol 22 (7) ◽  
pp. 470-482
Author(s):  
Samereh Ghazanfary ◽  
Fatemeh Oroojalian ◽  
Rezvan Yazdian-Robati ◽  
Mehdi Dadmehr ◽  
Amirhossein Sahebkar

Background: Boron Nitride Nanotubes (BNNTs) have recently emerged as an interesting field of study, because they could be used for the realization of developed, integrated and compact nanostructures to be formulated. BNNTs with similar surface morphology, alternating B and N atoms completely substitute for C atoms in a graphitic-like sheet with nearly no alterations in atomic spacing, with uniformity in dispersion in the solution, and readily applicable in biomedical applications with no obvious toxicity. Also demonstrating a good cell interaction and cell targeting. Aim and Objective: With a purpose of increasing the field of BNNT for drug delivery, a theoretical investigation of the interaction of Melatonin, Vitamin C, Glutathione and lipoic acid antioxidants using (9, 0) zigzag BNNTs is shown using density functional theory. Methods: The geometries corresponding to Melatonin, Vitamin C, Glutathione and lipoic acid and BNNT with different lengths were individually optimized with the DMOL3 program at the LDA/ DNP (fine) level of theory. Results: In the presence of external electric field Melatonin, Vitamin C, Glutathione and lipoic acid could be absorbed considerably on BNNT with lengths 22 and 29 Å, as the adsorption energy values in the presence of external electric field are considerably increased. Conclusion: The external electric field is an appropriate technique for adsorbing and storing antioxidants on BNNTs. Moreover, it is believed that applying the external electric field may be a proper method for controlling release rate of drugs.


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