Dear Pramod Subedi ,

please have a look at:

https://my.bruker.com/acton/attachment/2655/f-0e4f/1/-/-/-/-/

According to that 'Application Report XRD 13', the D2 Phaser is able to scan well below 5° in 2theta.

See also:

https://www.bruker.com/en/products-and-solutions/diffractometers-and-x-ray-microscopes/x-ray-diffractometers/d2-phaser.html

and go to the section:

'D2 PHASER Key Features'

and open option < 2/3> of the figures; entitled 'Superior low-angle and low-background performance'

Best regards

G.M.

Gerhard points to Bruker sales literature where they show a 0.6° - 5° 2θ with a peak just below 1°. Since it is sales literature from the manufacturer, you never know if you should believe it. I work for Proto Manufacturing - a small business with direct competitor offerings to Bruker's benchtop XRD instrument (see protoxrd.com). With Proto's AXRD benchtop, I personally have acquired data very similar to what Bruker shows at Gerhard's reference. So, I believe acquiring such data on that instrument is indeed possible. It will require using quite narrow slits and careful alignment of the slits, and you may not get usable data down to

Dear w.s.l. Boyer ,

thanks for your reply.

You mentioned a very essential aspect, which I forgot to write down above; grazing incidence requires a small cross-section of the primary beam, i.e. a small exit slit; otherwise the sample surface will be overexposed and the surroundings of the sample will add x-ray scatter onto the detector.

There might be hints in the manual about the slit widths*), which is appropriate in the low angle region.

A second thing is essential for the low angle region: very often a variable knife edge is used above the sample surface in order to a) prevent parts of the primary beam being picked up by the detector and b) to reduce the x-ray scatter from the air.

I do not know whether the 'Phaser' has got such an option at all.

*) both for the primary beam as well as for the detected beam.

Best regards

G.M.

Thanks Gerhard Martens and w.s.l. Boyer .