scholarly journals X-Ray induced Photostriction in Bismuth Ferrite

2014 ◽  
Vol 70 (a1) ◽  
pp. C162-C162
Author(s):  
Daniel Nye ◽  
Dean Keeble ◽  
Semen Gorfman ◽  
Mads Weber ◽  
Jens Kriesel ◽  
...  
Keyword(s):  
Thin Film ◽  
Piezoelectric Effect ◽  
Bismuth Ferrite ◽  
Potential Method ◽  
Photoelectric Effect ◽  
X Rays ◽  
Bismuth Iron Oxide ◽  
X Ray ◽  
Intrinsic Effect ◽  
Electronic And Structural Properties

In a material with both a piezoelectric effect and the capability to form a photocurrent, photostriction can be observed – the deformation of the crystal by light. When studying photostriction, a potential method is to use x-rays to probe the unit cell in response to another light source as a stimulus, such as a laser or a diode. Given that x-rays are also photons it is plausible that they themselves produce some effect. An experiment was carried out to investigate how significant the effects of the x-rays are in producing photostriction in the absence of any other source of illumination. The material studied in this example was bismuth iron oxide, BiFeO3. A thin film with electrodes was used and it was found that the photocurrent generated by a laboratory x-ray source on the sample was of comparable level to that of a laser or diode used in the study of the bulk photoelectric effect. Using a novel, time dependent crystallographic approach, the intrinsic effect of synchrotron x-ray light on a photoferroelectric thin film has been investigated. Furthermore, we have simultaneously collected diffraction and photoelectric data, and the correlation between the electronic and structural properties will be discussed. These results could suggest that caution is necessary when interpreting photostriction data obtained with the use of x-rays.

Problems in Thin-Film X-ray Quantification

1990 ◽  
Vol 48 (2) ◽  
pp. 458-459
Author(s):  
J N Chapman ◽  
W A P Nicholson
Keyword(s):  
Thin Film ◽  
Specimen Thickness ◽  
X Rays ◽  
Characteristic Peak ◽  
Local Composition ◽  
X Ray ◽  
Measured Ratio ◽  
Path Lengths ◽  
Composition Changes

Energy dispersive x-ray microanalysis (EDX) is widely used for the quantitative determination of local composition in thin film specimens. Extraction of quantitative data is usually accomplished by relating the ratio of the number of atoms of two species A and B in the volume excited by the electron beam (nA/nB) to the corresponding ratio of detected characteristic photons (NA/NB) through the use of a k-factor. This leads to an expression of the form nA/nB = kAB NA/NB where kAB is a measure of the relative efficiency with which x-rays are generated and detected from the two species.Errors in thin film x-ray quantification can arise from uncertainties in both NA/NB and kAB. In addition to the inevitable statistical errors, particularly severe problems arise in accurately determining the former if (i) mass loss occurs during spectrum acquisition so that the composition changes as irradiation proceeds, (ii) the characteristic peak from one of the minority components of interest is overlapped by the much larger peak from a majority component, (iii) the measured ratio varies significantly with specimen thickness as a result of electron channeling, or (iv) varying absorption corrections are required due to photons generated at different points having to traverse different path lengths through specimens of irregular and unknown topography on their way to the detector.

Structural dynamics of PZT thin films at the nanoscale

2005 ◽  
Vol 902 ◽  
Author(s):  
Alexei Grigoriev ◽  
Dal-Hyun Do ◽  
Dong Min Kim ◽  
Chang-Beom Eom ◽  
Bernhard Adams ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Lattice Distortion ◽  
Piezoelectric Effect ◽  
Polarization Switching ◽  
X Rays ◽  
Time Resolved ◽  
X Ray ◽  
Converse Piezoelectric Effect ◽  
Ferroelectric Capacitors ◽  
Crystal Lattice Distortion

AbstractWhen an electric field is applied to a ferroelectric the crystal lattice spacing changes as a result of the converse piezoelectric effect. Although the piezoelectric effect and polarization switching have been investigated for decades there has been no direct nanosecond-scale visualization of these phenomena in solid crystalline ferroelectrics. Synchrotron x-rays allow the polarization switching and the crystal lattice distortion to be visualized in space and time on scales of hundreds of nanometers and hundreds of picoseconds using ultrafast x-ray microdiffraction. Here we report the polarization switching visualization and polarization domain wall velocities for Pb(Zr0.45Ti0.55)O3 thin film ferroelectric capacitors studied by time-resolved x-ray microdiffraction.

scholarly journals Synchrotron X-ray Microdiffraction Images of Polarization Switching in Epitaxial PZT Capacitors with Pt and SrRuO3 Top Electrodes

2003 ◽  
Vol 784 ◽  
Author(s):  
Dal-Hyun Do ◽  
Dong Min Kim ◽  
Chang-Beom Eom ◽  
Eric M. Dufresne ◽  
Eric D. Isaacs ◽  
...  
Keyword(s):  
Thin Film ◽  
Bottom Electrode ◽  
Sputter Deposition ◽  
Ferroelectric Polarization ◽  
X Rays ◽  
X Ray ◽  
Pzt Film ◽  
Thin Film Capacitors ◽  
Pzt Thin Film ◽  
Switchable Polarization

ABSTRACTThe evolution of stored ferroelectric polarization in PZT thin film capacitors was imaged using synchrotron x-ray microdiffraction with a submicron-diameter focused incident x-ray beam. To form the capacitors, an epitaxial Pb(Zr,Ti)O3 (PZT) thin film was deposited on an epitaxially-grown conductive SrRuO3 (SRO) bottom electrode on a SrTiO3 (STO) (001) substrate. Polycrystalline SRO or Pt top electrodes were prepared by sputter deposition through a shadow mask and subsequent annealing. The intensity of x-ray reflections from the PZT film depended on the local ferroelectric polarization. With 10 keV x-rays, regions of opposite polarization differed in intensity by 26% in our PZT capacitor with an SRO top electrode. Devices with SRO electrodes showed just a 25% decrease in the remnant polarization after 107 switching cycles. In devices with Pt top electrodes, however, the switchable polarization decreased a by 70% after only 5×104 cycles.

Study on the Size Dependence of AuNPs in Enhancement Radiation Effect for Superficial Kilovoltage X-Rays

2019 ◽  
Vol 290 ◽  
pp. 81-86
Author(s):  
Nur Shafawati binti Rosli ◽  
Azhar Abdul Rahman ◽  
Azlan Abdul Aziz ◽  
Shaharum Shamsuddin ◽  
Suhana Arshad
Keyword(s):  
Radiation Therapy ◽  
Free Radicals ◽  
Radiation Effects ◽  
Radiation Effect ◽  
Photoelectric Effect ◽  
Enhancement Effect ◽  
X Rays ◽  
Dose Enhancement ◽  
X Ray ◽  
Mcf 7

Radiation therapy and chemotherapy remain the most widely used treatment options in treating cancer. Recent developments in cancer research show that therapy combined with high-atomic number materials such as gold nanoparticles (AuNPs) is a new way to treat cancer, in which AuNPs are injected through intravenous administration and bound to tumor sites has enhanced tumor cell killing. Radiation therapy aims to deliver a high therapeutic dose of ionizing radiation to the tumor without exceeding normal tissue tolerance. In this work AuNPs have been used for the enhancement of radiation effects on breast cancer cells (MCF-7) for superficial kilovoltage X-ray radiation therapy. The use of AuNPs in superficial kilovoltage X-ray beams radiation therapy will provide a high probability for photon interaction by photoelectric effect. These provide advantages in terms of radiation dose enhancement. In this work, MCF-7 cells were seeded in the 96-well plate and treated with 13 nm, 50 nm and 70 nm AuNPs before they were irradiated with 80 kVp X-rays beam at various radiation doses. Photoelectric effect is the dominant process of interaction of 80 kVp X-rays with AuNPs. When the AuNPs are internalized into the MCF-7 cells, the dose enhancement effect is observed. The presence of AuNPs in the MCF-7 cells will produce a higher number of photoelectrons, and resulting more “free radicals” that will lead to increase in cell death. Then, these free radicals will lead to DNA damage to the MCF-7 cells. To validate the enhanced killing effect, both with and without AuNPs MCF-7 cells is irradiated simultaneously. By comparison, the results show that AuNPs significantly enhance cancer killing and the enhancement radiation effect was dependent on the size of AuNPs.

Energy distribution of μd1s muonic atom and its spin states effecting on muonic X-Ray transfer yield in solid thin film method

2014 ◽  
Vol 23 (02) ◽  
pp. 1450006 ◽  
Author(s):  
R. Gheisari ◽  
M. Afshari ◽  
K. Khorshidian
Keyword(s):  
Thin Film ◽  
Energy Distribution ◽  
Muonic Atom ◽  
Rate Equations ◽  
Spin States ◽  
X Rays ◽  
X Ray ◽  
Solid Deuterium ◽  
Molecular Formation ◽  
Film Method

We have investigated the energy distribution of [Formula: see text] and its spin states (F) effecting on muonic X-ray transfer yield in the solid thin film method. Argon ( Ar ) ion has been considered as the implanted ion in solid deuterium (s D 2) layer at a temperature of T = 3 K. A kinetics model has been used, the corresponding rate equations have been constructed and our results of X-ray yield have been compared with recent measured data. The μd1s muonic atoms, which can take part in resonant molecular formation, have been separated from atoms participating in nonresonant reactions. On this basis, the integrated number of X-rays has been calculated. The results show that the effect of μd1s energy distribution on the number of X-photons is not serious, while its spin states strongly affect the muonic X-ray yield.

Determination of the Mechanical Response of Thin Films with X-Rays

1993 ◽  
Vol 308 ◽  
Author(s):  
I. C. Noyan ◽  
G. Sheikh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Response ◽  
Strain Analysis ◽  
Local Strain ◽  
X Rays ◽  
Stress Strain ◽  
X Ray ◽  
The Individual

ABSTRACTThe mechanical response of a specimen incorporating thin films is dictated by a combination of fundamental mechanical parameters such as Young's moduli of the individual layers, and by configurational parameters such as adhesion strength at the interface(s), residual stress distribution and other process dependent factors. In most systems, the overall response will be dominated by the properties of the (much thicker) substrate. Failure within the individual layers, on the other hand, is dependent on the local strain distributions and can not be predicted from the substrate values alone. To better understand the mechanical response of these systems, the strain within the individual layers of the thin film system must be measured and correlated with applied stresses. Phase selectivity of X-ray stress/strain analysis techniques is well suited for this purpose. In this paper, we will review the use of the traditional x-ray stress/strain analysis methods for the determination of the mechanical properties of thin film systems.

Interaction of ionizing radiations with matter

2015 ◽  
Author(s):  
Colin J Martin
Keyword(s):  
Radiation Dose ◽  
Scattered Radiation ◽  
Final Section ◽  
Radioactive Decay ◽  
Photoelectric Effect ◽  
X Rays ◽  
X Ray ◽  
Radiation Fields ◽  
Ionizing Radiations ◽  
Radiology Image

Interactions of ionizing radiations with matter are fundamental to the practice of radiation protection. They determine the magnitude and distribution of doses in tissues, the performance of detectors and imaging devices, and the attenuating properties of shielding materials. This chapter describes briefly the processes of radioactive decay and the properties of the various particles emitted, and then goes on to consider the interactions of radiation with matter. Electron interactions with metals result in bremsstrahlung and characteristic X-rays that form the basis of X-ray production. The interaction mechanisms of X-rays with tissue, particularly the photoelectric effect and Compton scattering, are inherent in the process of radiology image formation. Understanding the physics behind X-ray interactions so that scattered radiation can be taken into account is crucial in designing methods for accurately measuring radiation dose parameters. The final section deals with the dose related variables involved in measurement of radiation fields.

An Empirical Test Of A Thin-Film Analysis Routine On Bisrcacu Oxide Superconductor Precursors

1990 ◽  
Vol 48 (2) ◽  
pp. 236-237
Author(s):  
D.K. Ross ◽  
R.V. Heyman ◽  
D. Elthon
Keyword(s):  
Thin Film ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Empirical Test ◽  
X Rays ◽  
Film Analysis ◽  
X Ray ◽  
Analysis Techniques ◽  
Thin Film Analysis ◽  
Excitation Volume

Until quite recently, electron microprobe analysis techniques were limited to samples of “infinite” thickness, that is, to samples thick enough such that the entire excitation volume was contained within the material of interest. Thin film analysis was not possible with available matrix correction programs, which were based on the assumption of samples of “infinite” thickness. Now however, algorithms are available that permit analysis of thin samples.We have obtained one of the more versatile and sophisticated of these programs. In order to investigate the accuracy of this routine we have analyzed several BiSrCaCuO thin films at 15 kV and repeated the analysis at 30 kV. These films were thick enough such that at 15 kV conventional ZAF data reduction yielded acceptable totals (98-101 %) with minimal substrate x rays observed. At 30 kV, however abundant substrate x rays were observed and ZAF yielded very low totals. X-ray intensity ratios from 30 kV runs were used to estimate film thickness and matrix corrections were applied using the Waldo algorithm.

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