A maximum entropy method for determining column-length distributions from size-broadened X-ray diffraction profiles

Armstrong, N.; Kalceff, W.

doi:10.1107/s0021889899000692

Cited by 21 publications

(9 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the results from the Bayesian/MaxEnt method are in good agreement and address the limitations of the earlier work (see [ 30 , 10 ]), several important issues have been raised and are the subject of further investigation. These concern the accurate background estimation of the observed line profile and are very important; for example, the analysis of simulated data demonstrated how systematic errors affect the Fourier coefficients.…”

Section: Discussionsupporting

confidence: 66%

See 1 more Smart Citation

Bayesian inference of nanoparticle-broadened X-ray line profiles

Armstrong¹,

Kalceff²,

Cline³

et al. 2004

J. Res. Natl. Inst. Stand. Technol.

Self Cite

View full text Add to dashboard Cite

The analysis of x-ray line profile broadening can be considered as solving a series of inverse problems. There are usually two steps-removing the instrumental contribution (deconvolution), and determining the broadening contribution in terms of crystallite size and microstrain. Here we are concerned with quantifying only the size broadening, in terms of the shape and size distributions of the crystallites. We present a method that removes the instrumental broadening and determines the particle size distribution in a single step. The general theoretical framework developed makes it possible to determine the crystallite shape and average dimensions, and to fully quantify these results by also assigning uncertainties to them.In general, there are two approaches that can be adopted. The first assumes functional forms for the size distribution and shape of the crystallites, and applies least squares fitting to determine the parameters defining the size distribution [1,2]. For pragmatic reasons, this approach is often used to ensure numerical stability; however, it is based on an explicit assumption for the crystallite size distribution and does not take into account the non-uniqueness of the solution.The second approach takes into account the nonuniqueness of the problem of determining the size distribution P(D) from the experimental data, by assigning a probability to the solutions and enabling an average solution to be determined from the set of solutions; moreover, it also allows any a priori information and assumptions to be included and tested. This approach is

show abstract

Section: Discussionsupporting

confidence: 66%

“…This ensures that the statistics of the experimental data are transferred to quantifying the uncertainty in the solution. This approach also addresses a difficulty of the two-fold approach discussed by Armstrong & Kalceff (1999).…”

Section: Determining P (D) From G(s)mentioning

confidence: 99%

Bayesian inference of nanoparticle-broadened X-ray line profiles

Armstrong¹,

Kalceff²,

Cline³

et al. 2004

J. Res. Natl. Inst. Stand. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The full-width at half maximum (FWHM) for the (0002) ZnO peak is 0.18°, 0.19° and 0.18° for the ZnO films on Si, glass and PI substrates, respectively. The grain size of the ZnO films estimated by the Debye-Scherrer formula 39,41 is 48.2 nm, 45.7 nm and 51.2 nm for the ZnO films on Si, glass and PI, respectively, that are comparable to those well-performed ZnO films reported in other works 42,43 .…”

supporting

confidence: 83%

Comparative Study on Microfluidic Performance of ZnO Surface Acoustic Wave Devices on Various Substrates

Wang

Zhou

et al. 2014

J. Electrochem. Soc.

View full text Add to dashboard Cite

ZnO thin film-based surface acoustic wave (SAW) devices have been fabricated on Si, glass and polyimide (PI) substrates, and their microfluidic performances were compared. The Rayleigh and Sezawa mode waves were observed from the ZnO/Si devices, the Rayleigh and Lamb modes from the ZnO/PI, and only the Rayleigh mode from the ZnO/glass devices. The ZnO/Si devices have the best performance with the highest acoustic streaming velocity of about 10 cm/s and the shortest particle concentration time of less than 10 sec. The ZnO/glass SAW devices deliver comparable performances to that on Si substrate, while the ZnO/PI devices perform not as good as the devices on other two types of substrates due to the large acoustic attenuation, but still can deliver a streaming velocity up to 1.0 cm/s and reasonable particle concentration function with a particle concentration time of ~70 sec.Owing to its low cost, easy fabrication and compatible with traditional glass-based biochemical analysis systems, ZnO/glass SAW device is believed to have better potential for lab-on-a-chip application.In recent years, lab-on-a-chip (LOC) technology has attracted great attentions for research and development, and has been widely utilized in chemical, biological and medical applications. 1-8 Microfluidics including liquid transportation, pumping, mixing, digitizating etc, and sensors are the two main components of LOC microsystems. Various effects have been utilized to develop microfluidics such as bimorph structure, electrostatic and piezoelectric mechanisms. Moving part-free microfluidics based on kinetic energy such as electroosmosis, 9, 10 electrophoresis, 11, 12 dielectrophoresis 13, 14 etc are preferred owing to its advantages of excellent reliability, easy fabrication and operation etc.Surface acoustic wave (SAW) device is one of the building blocks for electronics and microsystems, 15-17 and can also be utilized for accurate sensing, efficient fluidic actuation and manipulation. 18-23 Therefore SAW-based microfluidic devices and sensors will play an important role in single mechanism based-LOCs in the future. SAW-based microfluidics have the advantages of low cost, high stability, easy fabrication and operation, 24 and have been intensively investigated and studied in recent years. Wixforth demonstrated the principle of SAW-based microfluidic. 25 Li et al demonstrated the particle concentration effect on LiNbO 3 substrate 26 and Alghane et al conducted numerical simulation for liquid mixing and particleconcentration. 27 They also discussed the frequency effect and scaling effect on the performance of SAW-based microfluidics. 28,29 Shi et al showed that standing surface acoustic wave (SSAW) can be used for particle sorting and manipulation. 30 Reboud et al reported the ability to do cell lyses using SAW on LiNbO 3 substrate. 31 One of the key issues for widespread application of LOCs and microfluidics is the cost of the materials and devices involved, which is the same for the SAW-based microfluidics and LOCs. At the early study, SAW-based...

show abstract

“…From pure physical line profile the Ê α -doublet peaks position and integral breadths of lines were determined. An average size of crystallites D was approximately calculated from the integral breadth of Ê α1 line using Sherrer equation [7,8]:…”

Section: Resultsmentioning

confidence: 99%

Structural investigations of annealed ZnS:Cu, Ga film phosphors

Lytvyn¹

2001

Semicond. Phys. Quantum Electron. Optoelectron.

View full text Add to dashboard Cite

X-ray and atomic force microscopy techniques were used for investigations of crystalline structure and nano-morphology of ZnS:Cu thin films. The films were deposited by electron beam evaporation on substrates of various types (glass, BaTiO 3 , silicon). New nonvacuum method of annealing was applied for improvement electro-physical parameters of ZnS:Cu based thin film electroluminescent devices. The annealing was carried out at the temperature of 850 °C. Ga co-doping was applied for the same structures in the course of the annealing process. It was shown that recrystallization process at annealing leads to improvement of ZnS:Cu films structural perfection without changes of crystal structure. This improvement provides tenfold increase of photo-and electroluminescence brightness and decrease of threshold voltage down to 10 V, as well as enhancement of device stability against degradation.

show abstract

A maximum entropy method for determining column-length distributions from size-broadened X-ray diffraction profiles

Cited by 21 publications

References 21 publications

Bayesian inference of nanoparticle-broadened X-ray line profiles

Bayesian inference of nanoparticle-broadened X-ray line profiles

Comparative Study on Microfluidic Performance of ZnO Surface Acoustic Wave Devices on Various Substrates

Structural investigations of annealed ZnS:Cu, Ga film phosphors

Contact Info

Product

Resources

About