How to Identify Phases and Miller Indices in XRD Data?

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Discussion Overview

The discussion focuses on analyzing X-ray diffraction (XRD) data for phase identification and particle size calculation, exploring various methods and formulas, including the Debye-Scherrer formula and Rietveld analysis. Participants share their experiences and seek advice on improving their calculations and understanding of the data.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant inquires about advanced methods for analyzing XRD data beyond the Debye-Scherrer formula for particle size calculation.
  • Another participant requests additional details about the experimental setup, including the system under study, expected phases, and available software for analysis.
  • A participant describes their use of the Debye-Scherrer formula and provides the equation used for particle size calculation, highlighting its limitations under certain conditions.
  • Concerns are raised about the accuracy of particle size calculations when stress-related and instrument-related broadening are present, suggesting a more complex analysis may be necessary.
  • One participant expresses difficulty in obtaining proper results with the Debye-Scherrer formula and seeks guidance on potential errors in their calculations.
  • Another participant suggests including raw data and calculations for further examination and offers to help analyze the results.
  • Discussions include the importance of Gaussian fitting for peak analysis and the potential impact of scan speed on data quality.
  • Participants discuss the specific equipment used, including the PANalytical X-ray diffractometer and Philips 1830, and the type of X-ray source (Cu-K_alpha1).
  • Several participants share their experiences with particle size measurements and the challenges faced in achieving consistent results.

Areas of Agreement / Disagreement

Participants express varying opinions on the effectiveness of the Debye-Scherrer formula and the necessity of more advanced methods. There is no consensus on the best approach to analyze the data, and multiple competing views on the accuracy of the calculations remain unresolved.

Contextual Notes

Limitations include potential errors due to instrument-related broadening, the need for careful separation of broadening effects, and the dependency on the specific conditions of the samples analyzed.

  • #61
Hi,
just wondering if anyone can help with these questions:

The XRD spectrum (attached) for stainless steel (Fe) was obtained using x-rays of wavelength 0.154 nm.
Use the upper spectrum for this analysis.
(a) Use the first two peak positions to determine the value of the lattice constant, “a” for Fe ( Fe is FCC).
(b) Confirm the identity of the labels - e.g. the (2 0 0 ) etc – of the other three peaks (using the lattice constant determined in (a)).

Much appriciated
Sarah
 

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  • #62
Hi Friends. I don't know much about XRD. Is there anybody help me know:
how can we understand the percent of crystalinity from peaks
thanks
hamid
 
  • #63
Hi
I am new to XRD. Can anyone please guide me how to anlayse the data. I am trying to identify and quantify microstructural phases in iron, i,e residual austenite, ferrite, martensite if any. I have sample data as below. I have no clue what those number mean and i have been adviced to use a peak fitting program to analyse the data. Can anyone please help?

41.5050 37.0
41.5150 37.0
41.5250 43.0
41.5350 34.0
41.5450 35.0
41.5550 23.0
41.5650 31.0
41.5750 31.0
41.5850 36.0
41.5950 29.0
41.6050 28.0
41.6150 34.0
41.6250 36.0
41.6350 30.0
41.6450 31.0
41.6550 34.0
41.6650 40.0
41.6750 31.0
41.6850 29.0
41.6950 28.0
41.7050 32.0
41.7150 43.0
41.7250 38.0
41.7350 34.0
41.7450 40.0
41.7550 45.0
41.7650 42.0
41.7750 40.0
41.7850 26.0
41.7950 41.0
41.8050 41.0
 
  • #64
Hi guys, as I know that the debye-scherrer formula is only to measure crystallite size but not for particle size. crystallite is different from particle.
 
  • #65
Hi,
I am research scholar in physics. I am new to XRD analysis. I have XRD of YBaCuO system.
How to analyse? please help me.

K.Srinivasan
Email: srinivasan629@gmail.com
 
  • #66
kpullab said:
Hai Gokul,

I am sending you a word file as i cannot attach an Excel file. So as soon as you receive my attachment you have to change the extension to"Grain size.xls".I calculated the grain size of both as received and 10 hrs of ball milled powder. I hope you can understand my calculation. If not please let me know. I have also enclosed charts in them, you can have a look at them too.
Thank you
krishna priya

Hi,
I've read your data and found that you don't half-divide the FWHM value in the crystal size calculation. I've found a book that said that it has to be divided by 2 in the calculation because the value is still in 2-theta region while the calculation is in theta region. By doing this than you'll find your result twice of your earlier value (about 61 nm for as-received powder and 39.5 nm for the ball-milled)
 
  • #67
Dear Friend, i am student and have following data
2θ in degrees: 17.96, 29.85, 35.27, 37.16, 42.76, 53.36, 56.64, 62.47, 70.58, 74.34, 79.20, 86.60 and 89.86

Can you please help me in finding what compound it is (Hint: one kind of compounds having iron element)
 
  • #68
Is percent composition of αPbO & βPbO in Lead Oxide(Red Oxide) samples can be determined by XRD techniques.
 
  • #69
Dear Professor
Hello
I have some questions about XRD pattern of nanoparticle:
1- What is the different between bulk XRD AND nano particle XRD ?
2- Why is the XRD pattern of nanoparticle has broad peak?


Best regards
 
  • #70
sky1 said:
Dear Friend, i am student and have following data
2θ in degrees: 17.96, 29.85, 35.27, 37.16, 42.76, 53.36, 56.64, 62.47, 70.58, 74.34, 79.20, 86.60 and 89.86

Can you please help me in finding what compound it is (Hint: one kind of compounds having iron element)
Your Pattern is very likely some kind of magnetite

http://rruff.geo.arizona.edu/AMS/xtal_data/DIFfiles/00955.txt
http://rruff.geo.arizona.edu/AMS/xtal_data/DIFfiles/04829.txt
http://rruff.geo.arizona.edu/AMS/xtal_data/DIFfiles/07612.txt
 
  • #71
dear friends,
i'm new to XRD and i have some data to analyse..
However, i think that something is wrong with the analysis...could you help me when comparing the results from the pattern of a reference i found in a book...
It has to do with a zeolite material...
I'm desperate!
HELP!
If you want i can provide you with the raw data as they gave me from the lab
 
  • #72
i have one antimony dross(generated from lead smelting) sample for XRD analysis i have run it but what next how to analyse this data? can somebody help? what phases it is having ?
i am new one in XRD please help.
 
  • #73
pl tell me whether we can get directly the compound existing in an alloy by xrd technique
 
  • #74
hi, could anyone help please ?I have a question ,how to identify miller index in a XRD pattern , I don't have an analysis program,my material is a poly crystal ,and mainly reported to have an orthorohombic and tetragonal structure, it is cu k α (alfa) I also don't know how to identify which 2 theta angel is belongs to which phase of my substance . thanks
 

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