Re: [EXT] Re: [External] Re: Step-like basline

Can be modeled in the BGMN peak profile model as well, by modifying the *.lam file by a series of additional Lorentzians on the 1/lambda scale, see figure. The same can be done for other spectral impurities, e.g. W L satellites. Also "electronic effects" on the wavelength distribution profi

Re: [EXT] Re: [External] Re: Step-like basline

Topas can model them quite well. The functionality was introduced in version 5. On Mon, 4 Sep 2023, 00:54 Kurt Leinenweber, wrote: > Hi, Are these things modeled in Rietveld programs, by chance? It seems > like a lot of baggage to put in a refinement but if it makes the results > better… > > >

Re: [EXT] Re: [External] Re: Step-like basline

I agree, it does look more like an absorption edge than tube tails (not enough coffee yet at 7AM). But tube tails will be there in addition. I do not have the absorption edge problem on my primary instrument as we do not use a PSD or a beta filter, but we easily see tube tail effects on very int

Re: [EXT] Re: [External] Re: Step-like basline

Sorry for the error in my previous mail: the detector was of course an X'celerator, not Accelrys. Apologies El dom, 3 sep. 2023 21:02, miguel gregorkiewitz escribió: > Forgot to say that the problem is absent in diffractometers with > monochromator. I observed it first in a bragg-brentano diffr

RE: [EXT] Re: [External] Re: Step-like basline

It can be modeled in Topas James P. Cline Materials Measurement Science Division National Institute of Standards and Technology 100 Bureau Dr. stop 8370 [ B113 / Bldg 217 ] Gaithersburg, MD 20899-8523USA james.cl...@nist.gov https://www.nist.gov/people/james-p-cli

Re: [EXT] Re: [External] Re: Step-like basline

Forgot to say that the problem is absent in diffractometers with monochromator. I observed it first in a bragg-brentano diffractometer with accelrys linear position sensitive detector (panalytical) which had no monochromator El dom, 3 sep. 2023 20:47, miguel gregorkiewitz escribió: > Kbeta can

Re: [EXT] Re: [External] Re: Step-like basline

Kbeta can always be added, but for the absorption edge there seems to be no remedy, and as seen in the graph, it is far more important El dom, 3 sep. 2023 18:54, Kurt Leinenweber escribió: > Hi, Are these things modeled in Rietveld programs, by chance? It seems > like a lot of baggage to put

RE: [EXT] Re: [External] Re: Step-like basline

Hi, Are these things modeled in Rietveld programs, by chance? It seems like a lot of baggage to put in a refinement but if it makes the results better... * Kurt From: rietveld_l-requ...@ill.fr On Behalf Of Thomas Gegan Sent: Sunday, September 3, 2023 9:16 AM To: Bish, David L ; Shay Tir

RE: [EXT] Re: [External] Re: Step-like basline

I agree with a Ni absorption edge, possibly with a Kβ peak around 38° 2θ. Tom Gegan Chemist III Phone: +1 732 205-5111, Email: tom.ge...@basf.com Postal Address: BASF Corporation, , 25 Middlesex Essex Turnpike, 08830 Iselin, United States [cid:image001.png@01D9DE60.71B

RE: Step-like basline

Yes; not the tube tails, however. James P. Cline Materials Measurement Science Division National Institute of Standards and Technology 100 Bureau Dr. stop 8370 [ B113 / Bldg 217 ] Gaithersburg, MD 20899-8523USA james.cl...@nist.gov https://www.nist.gov/people/jame

Re: Step-like basline

That's a k beta peak followed by a metal foil absorption edge followed by the K alpga peak. On Sun, 3 Sep 2023, 14:50 Shay Tirosh, wrote: > Dear Rietvelders > I am attaching a zoom-in on a diffraction profile. > My question is what is the origin of the step-like profile next to a very > large re

Re: [External] Re: Step-like basline

Hello Shay, I think it is probably related to "tube tails". You can read about this in the literature (e.g., on the BGMN web site) and you can model it in some Rietveld software such as Topas. You don't normally notice this but it becomes apparent with higher-intensity peaks. Regards, Dave

Re: [EXTERNAL] Step-like basline

Dear Shay, Do you use CuKalpha radiation or the like? Try to get the wavelength for the step and the peak at left. I guess they are the absorption edge of a filter and Kbeta, respectively. Best Miguel El dom, 3 sep. 2023 9:12, Yoji Kobayashi escribió: > Dear Shay, > > Does your diffractomet

Re: [EXTERNAL] Step-like basline

Dear Shay, Does your diffractometer have a Ni foil filter (to cut K-beta radiation)? The absorption edge of Ni often results in this “step” near any strong diffraction peak; it is quite normal for such arrangements. Best, Yoji == Yoji Ko

Re: Step-like basline

Hey Shay, Are you using a motorized slit during the measurement? These may open up abruptly to compensate for the angular dependence of the footprint and thus generate an abrupt increase in the intensity. Hope it helps :) On Sun, Sep 3, 2023, 8:50 AM Shay Tirosh wrote: > Dear Rietvelders > I