scholarly journals Reversible oxygen migration and phase transitions in hafnia-based ferroelectric devices

Science ◽  
2021 ◽  
pp. eabf3789
Author(s):  
Pavan Nukala ◽  
Majid Ahmadi ◽  
Yingfen Wei ◽  
Sytze de Graaf ◽  
Evgenios Stylianidis ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Transitions ◽  
Dielectric Layer ◽  
Atomic Resolution ◽  
Exact Nature ◽  
Oxygen Imaging ◽  
Oxygen Migration ◽  
Source Sink ◽  
Source And Sink

Unconventional ferroelectricity exhibited by hafnia-based thin films, robust at nanoscale sizes, presents tremendous opportunities in nanoelectronics. However, the exact nature of polarization switching remains controversial. We investigated La0.67Sr0.33MnO3/Hf0.5Zr0.5O2 capacitor interfaced with various top electrodes while in situ electrical biasing using atomic resolution microscopy with direct oxygen imaging, as well as synchrotron nanobeam diffraction. When the top electrode is oxygen reactive, we clearly show reversible oxygen vacancy migration with electrodes being the source and sink of oxygen, and the dielectric layer acting as a fast conduit at millisecond timescales. With non-reactive top electrodes and at longer time scales (seconds), the dielectric layer also acts as an oxygen source/sink. Our results show that ferroelectricity in hafnia-based thin films is unmistakably intertwined to oxygen voltammetry.

scholarly journals In-situ Atomic-Resolution Observations of Oxide-Reduction Induced Formation of Nano-Holes in Cu2O Thin Films

2018 ◽  
Vol 24 (S1) ◽  
pp. 1816-1817
Author(s):  
Xiaobo Chen ◽  
Dongxiang Wu ◽  
Lianfeng Zou ◽  
Qiyue Yin ◽  
Hanlei Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Resolution ◽  
Oxide Reduction ◽  
Cu2o Thin Films

Atomic resolution in situ observation on photon-induced reshaping and phase transitions of CsPbBr3 nanocube and quantum dot

2021 ◽  
Vol 119 (20) ◽  
pp. 203103
Author(s):  
Jiayi Li ◽  
Yifeng Ren ◽  
Yucong Su ◽  
Zhongnan Xi ◽  
Yurong Yang ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Quantum Dot ◽  
Atomic Resolution ◽  
In Situ Observation

scholarly journals An optimized sample preparation approach for atomic resolution in situ studies of thin films

2018 ◽  
Vol 81 (11) ◽  
pp. 1250-1256 ◽  
Author(s):  
Adele Moatti ◽  
Ritesh Sachan ◽  
John Prater ◽  
Jagdish Narayan
Keyword(s):  
Thin Films ◽  
Sample Preparation ◽  
Atomic Resolution ◽  
In Situ Studies

Use of Atom Beama Scattering to Study Structures of and Phase Transitions in Ultra-Thin Films

1990 ◽  
Vol 208 ◽  
Author(s):  
G. Vidali ◽  
W. LI ◽  
J.-S. Lin ◽  
C. Moses
Keyword(s):  
Thin Films ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Beam Scattering

ABSTRACTWe have used neutral helium beam scattering to probe structural and thermodynamic properties of in-situ deposited ultra-thin films of metals on well characterized substrates. We show the capabilities of this technique by presenting some recent results of our studies of Hg adsorption of Cu(001) and on monolayer phases of Pb on Cu(001).

scholarly journals Measuring phase transitions in La1-xSrxCoO3 using in-situ atomic-resolution Z-contrast imaging and EELS

2013 ◽  
Vol 19 (S2) ◽  
pp. 1922-1923
Author(s):  
A. Gulec ◽  
R.F. Klie
Keyword(s):  
Phase Transitions ◽  
Atomic Resolution ◽  
Contrast Imaging ◽  
Z Contrast

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Nucleation and Early Growth of Sputtered thin Films

1970 ◽  
Vol 28 ◽  
pp. 516-517
Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
Ion Beam ◽  
Ion Source ◽  
Water Cooling ◽  
Stages Of Growth ◽  
Lens Assembly ◽  
Microscope Technique ◽  
Ion Beam Sputter Deposition

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

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