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 intense reflections.
We do not yet know Shay's instrumental configuration, but I assume he is using a PSD with a K-beta filter. How important the effects are in his pattern is open to discussion/argument. If tube tails are modeled, then the absorption edge effect is minor and is probably sufficiently removed from peak centroids that it will not significantly affect profile parameters; a test would be easy. I imagine that the effects in question would not be very noticeable on a linear plot with the intense peak on scale. But, as Jim said, these effects can also be modeled. The contribution from K-beta (and any other "extra" radiations, e.g., W) can and should always be modeled. Dave ________________________________ From: miguel gregorkiewitz <gregorm...@gmail.com> Sent: Sunday, September 3, 2023 3:02 PM To: Kurt Leinenweber <ku...@asu.edu> Cc: Thomas Gegan <tom.ge...@basf.com>; Bish, David L <b...@indiana.edu>; Shay Tirosh <stiro...@gmail.com>; Fernando Igoa <fer.igoa.1...@gmail.com>; Rietveld List (rietveld_l@ill.fr) <rietveld_l@ill.fr> Subject: 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 <gregorm...@gmail.com<mailto:gregorm...@gmail.com>> escribió: 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 <ku...@asu.edu<mailto:ku...@asu.edu>> escribió: 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<mailto:rietveld_l-requ...@ill.fr> <rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr>> On Behalf Of Thomas Gegan Sent: Sunday, September 3, 2023 9:16 AM To: Bish, David L <b...@indiana.edu<mailto:b...@indiana.edu>>; Shay Tirosh <stiro...@gmail.com<mailto:stiro...@gmail.com>>; Fernando Igoa <fer.igoa.1...@gmail.com<mailto:fer.igoa.1...@gmail.com>> Cc: Rietveld List (rietveld_l@ill.fr<mailto:rietveld_l@ill.fr>) <rietveld_l@ill.fr<mailto:rietveld_l@ill.fr>> Subject: 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<mailto:tom.ge...@basf.com> Postal Address: BASF Corporation, , 25 Middlesex Essex Turnpike, 08830 Iselin, United States [X] From: rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr> <rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr>> On Behalf Of Bish, David L Sent: Sunday, September 3, 2023 7:08 AM To: Shay Tirosh <stiro...@gmail.com<mailto:stiro...@gmail.com>>; Fernando Igoa <fer.igoa.1...@gmail.com<mailto:fer.igoa.1...@gmail.com>> Cc: Rietveld List (rietveld_l@ill.fr<mailto:rietveld_l@ill.fr>) <rietveld_l@ill.fr<mailto:rietveld_l@ill.fr>> Subject: [EXT] Re: [External] Re: Step-like basline Some people who received this message don't often get email from b...@indiana.edu<mailto:b...@indiana.edu>. Learn why this is important<https://urldefense.com/v3/__https:/aka.ms/LearnAboutSenderIdentification__;!!IKRxdwAv5BmarQ!fFhSHn4S5iEzkW-O9lvWG-OzoqK_2SKhRniGa71nxuOL3GcxiyD83i2mnNN0Z48HPkn4zjKqH-aqqA$> 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 ________________________________ From: rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr> <rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr>> on behalf of Fernando Igoa <fer.igoa.1...@gmail.com<mailto:fer.igoa.1...@gmail.com>> Sent: Sunday, September 3, 2023 3:06 AM To: Shay Tirosh <stiro...@gmail.com<mailto:stiro...@gmail.com>> Cc: Rietveld List (rietveld_l@ill.fr<mailto:rietveld_l@ill.fr>) <rietveld_l@ill.fr<mailto:rietveld_l@ill.fr>> Subject: [External] Re: Step-like basline This message was sent from a non-IU address. Please exercise caution when clicking links or opening attachments from external sources. 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 <stiro...@gmail.com<mailto:stiro...@gmail.com>> 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 reflection peak? Is it a sample preparation problem? Is it part of the baseline? [X] Thanks Shay -- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com<mailto:alan.he...@neutronoptics.com>> Send commands to <lists...@ill.fr<mailto:lists...@ill.fr>> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/<https://urldefense.com/v3/__http:/www.mail-archive.com/rietveld_l@ill.fr/__;!!IKRxdwAv5BmarQ!fFhSHn4S5iEzkW-O9lvWG-OzoqK_2SKhRniGa71nxuOL3GcxiyD83i2mnNN0Z48HPkn4zjJTf8rNHg$> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr<mailto:lists...@ill.fr>> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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