For the case you mentioned the total time could be calculated from: 90-10 =80° divided by 0,5°/min this is 160 min

If you divide 80° degrees by 0.02° steps, so the total time will be 160x50 min? Is it logical?

Thanks dear Svoboda.

Hello, Dear murat

You should ask your operator for the 2theta degree step and the spent time for each step. Then with counting the total steps to the time duration for each step, you can calculate the measurement XRD time.

With the best regards 

Hii Murat,

The total time is determined by the speed of 0.5°/min. You can scan with a step of 0.02° or 0.01°, if you keep the same speed of 0.5°/min, you have already same time independent of step.

If you have a speed of 0.5°/min, for scanning 1° you need 2 minutes. So if you want to scan 90°-10°=80° you need 2minx80=160 min.

Is there a mistake?

Thanks Dear Dr.Atli.

Are the scan steps and scan speed  same parameters?

Thank you.

I am not a master of XRD.

But, the scan speed, as it is said, is a speed (°/min) however scan step is in degree, which is a kind of resolution that you want to have. If you plot your XRD diffractogram you will have a point at each 0.02° if you put a scan step of 0.02°. So if you want to scan from 10° to 90°, you will have (90-10)/0.02=4000 data points for 0.02° as scan step and if you use 0.04° for a scan step you will have only 2000 points separeted by a step of 0.04°. 

Then, scan speed is diffrent than scan step. 

No, the scan step is not the same as the scan speed. The scan step is measured in degrees 2-theta and you have 0.02, the scan speed is measured either in seconds per step or degrees per minute.

The total time can also have a different meaning if you are using a strip detector. For example I have a detector with 176 active channels for a step size of 0.02 degrees and a scan speed of 0.1 seconds per step from 10-90 it would calculate as 4000 steps and take about 7 minutes real time to complete, BUT the 'Totaltime' or time per step as reported by the software is 17.6 seconds since it is 176 x 0.1 so the effective total time would be 17.6 x 4000, that is 70400 seconds!

So reporting in degrees per minute does not make it very easy to compare between systems with strip detectors and point counters. If you are trying to recreate someone elses operating conditions it will also be necessary to take into account the type of detector used.

OK Murat! Touchy, I see!  Your are welcome. I just feel like Rip old boy when I see folks in the top echelon of R&D using technology at least as old as the Braggs still in modern times. You do have plenty of expert opinion about a fundamental question that should have been clear on "day one" with a diffractometer! Remain open to current technology in XRD. Good Luck!

Dear friend,

you erased your comment.

Do not publish the things if you will erase.

If I was born in a country that have opportunities, I would learn and use everything that I was capable.

You wrote injurious comments and I responded.

Kindly regards.

All of us are born in countries with opportunities. Fortunately, I was born in "free" India and live in the "freedom" of the USA. Some of us are able to find the opportunities others do not seek them. Even those that were born when the earth was "flat" risked their lives to prove that the earth was "round". http://en.wikipedia.org/wiki/Galileo_Galilei

Others like Hippocrates, the father of modern medicine, suffered terminal incarceration for holding on to their convictions, "Let thy food be thy medicine and thy medicine be thy food": http://en.wikipedia.org/wiki/Hippocrates

Notice how I've used both web links and JPEG files as attachment to this note. It is to illustrate the capability in RG for the others to take advantage as well. Add illustrative examples to your posts to make it easier & interesting for the rest of us to follow.

No problem Murat! No injury was meant. I notice a tremendous amount of expertise in Turkey w.r.t. materials science and XRD. Thankfully the contents in RG may be edited at will. I removed my prior post just to ease your concerns. If you demand it be re-posted, I'll tone it down and post the neutered content :-) The comment only made light of the current state of technology in most XRD labs even here in the US. BTW I did ask my professor Sigmund Weissmann (Rutgers) to replace the Geiger counter with a 2D detector in the early 1980's. His tool of preference even in those days was the photographic film since the 1950's.

I did see some really advanced XRD instrumentation recently at both the Indian Institute of Science Bengaluru and The Bose Institute Kolkata. These fellows are moving forward rapidly. They're shooting for the STARS and reaching MARS :-)

If you are working and intend to continue working with XRD, I seriously recommend investigating the use of modern 2D detectors.  Here is a great book for your collection and this is my favorite excerpt from it:

X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Great book! Worth acquiring for your XRD collection.

(pp. 162-163) 6.3.5. "Comparison between the Photographic and Counter Methods

It is obvious that the Geiger Counter and the ionization chamber have the advantage of precision and sensitivity. They alone permit a quantitative study of scattering. However, point by point measurements in reciprocal space are lengthy, while the photographic method gives directly a picture of the scattering in a single experiment over a large surface of reciprocal space. The resolving power of the film is excellent. Thus, sharply defined scattering regions, for example on rows or on planes of reciprocal lattice, show up very clearly on photographic film but are difficult to detect with a counter.

Let us note also that the counter is "blind". In many cases inaccuracies in the setup produce stray scattering which is easy to detect on the photographic film but which can spoil a series of experiments made with a counter.

The two methods are therefore complimentary and it would not be advisable to neglect one in favor of the other. The photographic method is admirably suited to the qualitative exploration of an unknown pattern, since one can then find totally unexpected phenomena. The counter is necessary for quantitative measurements on a pattern which is already known qualitatively."

This was printed in 1962. This has to be considered in light of the present day 2D detectors that combine the benefits of the counter & the film in one. These writings indicate some causes for the present day inertia of moving from the 0D to the modern 2D detectors. The spatial "blindness" of the 0D scintillation counter/detector is the principal reason even experienced experts using XRD are ambivalent about the 0D XRD data/results.

http://en.wikipedia.org/wiki/Galileo_Galilei

http://en.wikipedia.org/wiki/Hippocrates

On Monday October 20th, 2014, we hope to conduct a direct comparison of results from a 0D (point counter) system and a 2D real time XRD detector at the Indian Institute of Science Bengaluru. We plan to scan both corundum and silicon (Si) powder standards with the 2 methods then compare and contrast quantitatively. Time for scan, resolution, sensitivity to preferred orientation, sensitivity to particle size, sensitivity to Nano structural strain, beam conditioning, slit dimensions, etc. are some of the parameters we intend to monitor. We will be using a Bruker D8 with Bragg-Brentano focusing optics. BTW we intend to use "10-90o 2θ values" as well. We intend to share this data for public expert scrutiny once we have it. Please forward any suggestions to ensure unequivocal results to: [email protected]

Thank  you Dear all contributors for the first part, and Dear Ravi for innovative, illuminating , and guiding informations for the last part.

I hope I find the book you suggested , Dear Ravi.

Do you have a event web link for your 

Murat! Great to see such a tremendous paradigm shift. Appreciate you overcoming the initial antagonism and reaching out as you have done. We could avoid wars if more of us did so more often.  Dropping our egos a bit, I mean :-)

Included is a link to the LinkedIn Group "X-ray Diffraction Imaging for Materials Microstructural QC", where we will display data and details from the calibration/alignment test with Bruker D8 Bragg-Brentano optics on Monday October 20, 2014 at the Indian Institute of Science (IISc) Bengaluru. BTW IISc was founded under the "tyranny" of Britain at that time and was founded by J.R.Tata http://en.wikipedia.org/wiki/Jamsetji_Tata - Jamsetji Tata, a great Indian patriot of Iranian origin (Parsi, Zoroastrian) who's ancestors (akin to the modern day Yazidis of Iraqi/Kurd areas) had to flee their homeland due to persecution. Close-mindedness! Flat Earthers living in yesteryears :-)

Do feel welcome to join and share your expertise with us on LinkedIn. https://www.linkedin.com/groupItem?view=&gid=2683600&type=member&item=5926633764212994051&trk=groups_most_recent-0-b-ttl&goback=%2Egmr_2683600

Here is the Ebay link to the book. You will find it for sure! http://www.ebay.com/itm/X-Ray-Diffraction-In-Crystals-Imperfect-Crystals-and-Amorphous-Bodies-by-/380823738401?pt=US_Texbook_Education&hash=item58aadd1821

http://www.iisc.ernet.in/about-iisc/generalinformation.php

http://www.ebay.com/itm/X-Ray-Diffraction-In-Crystals-Imperfect-Crystals-and-Amorphous-Bodies-by-/380823738401?pt=US_Texbook_Education&hash=item58aadd1821

http://en.wikipedia.org/wiki/Jamsetji_Tata

Murat! How far off would it be experimentally to have "0.02° steps and 0.5°/min speed" from 2 hrs. and 40 min? At what "dwell time", would be my instinctive query. I'll pay attention and have it checked out on Monday at IISc. I have to answer nearly the same "age old" question in any case for our scenario as well.

With our 2D real time detector at 30fps (frames per second), @32um spatial resolution and 25mm diameter X-ray input window would require roughly 4000 data points (frames) on the Bragg profile. That will translate to about 134 seconds. Just a little more than 2.25 minutes. At 0.001 degree per step, it would create 80,000 data points over the 80 degrees scan. That would probably require roughly 2667 seconds or 45 minutes. 3D reciprocal space data with each frame up to 816x816 pixels and 16Bit dynamic range. This is precisely what we hope to achieve on Monday with the Silicon and Corundum standard powders. We will repeat the scan under the same circumstances with the conventional 0D detector system and present the comparison to the world of XRD a century after the Braggs' Nobel Prizes  https://www.flickr.com/photos/85210325@N04/11604959265/in/set-72157645018820696

Now you may understand why I feel like good old Rip Van Winkle perhaps :-) https://www.flickr.com/photos/85210325@N04/11343736043/in/set-72157645018820696

We developed this technology back in 1984-1988. I come back after a 3 decade sabbatical and still find the XRD community in Noah's arc and still in an life-embrace with the "stone ages" of XRD :-) What the Haven is going on...........? Let us tell the youngsters interested in XRD as a precise quantitative tool the whole story! No holding back. Progress does not hit us in the face, we must seek and grab it in our own interest!

Liberating the XRD community at large from the imprisonment in antiquity is our  motive and mission statement :-) Prisoner of the Past or Pioneer of the Future?

https://www.flickr.com/photos/85210325@N04/10221065324/in/set-72157645018820696

D. Yazici! Do you know of the late Dr. Rahmi Yazici of Stevens Institute of Technology?

Dear Ravi, 

I do not have experience about measurement. I only make lattice parameter calculations by the help of FullProf. I was inspecting the data quality through the scan parameters. 

Murat! I understand. No problem. Just beware there is a plethora of information in XRD that has traditionally been neglected.  I suggest you consider XRD as an essential NDE tool to characterize the Nano structure of your materials in the 2D real time mode.

I see you have done some interesting work with super conducting and magnetic materials.

Do you have facilities to grow epitaxial films of these materials?

Is preferred orientation observed in these materials? Is it desirable?

What is the end-use of such materials?