Sample Preparation

LDRX junho 2021

In the photo of the sample preparation bench at the LDRX – UFSC are the Si zerobackground (ZB) sample holders, 2 of the 3 towers for up to 15 holders each, in addition to other holders available at the LDRX-UFSC.

Usually, the preparation of samples for powder diffractometry is simple and the sample can be recovered after the XRD measurement since it is a non-destructive technique. However, here are some tips.

Powder diffraction:  Analysis and quantification of phases, crystallite size, microstrain, etc.

For this type of measurement, LDRX disposes:

  • stain-steel cavity sample holder (16mm and 27 mm diameter x 3mm deep) to be filled by the sample in finely powdered form (preferably with particles <150 microns: sieved and pre-grinding, if necessary/possible). Demo  here.
    Porta-amostras de aço inox PW1811/xx
    Si Zero background to measure a very small amount of sample using a sample holder Silicon zerobackground (in this case is even more important to have an ultra-fine powder <50 microns).  Demo here.
     Porta-amostras PW1813_xx para Si-ZB
    stain-steel /teflon rings (3 un.) para acomodar filmes ou amostras sólidas entre folhas de kapton (polimero amarelado);
    Porta-amostras filmes ou sólidos entre kaptons
    Capillary glass or quartz.  ultra fine powder <150 microns. Demo here

    Capilares para medidas em transmissão

     The collection time is inversely proportional to the amount of powder used, the smaller the sample´s amount, the longer the time to obtain data with good statistics and, consequently, the higher the cost.

See an article discussing the influence of the different LDRX-UFSC sample holders in the case of cement:

Paulo R. de Matos, José S. Andrade Neto, C. E. M. Campos, Is the R index accurate to assess the preferred orientation of portlandite in cement pastes? Construction and Building Materials, 292 (2021) 123471.

Fig. 2. Sample types used. (a) 27 mm with backload; (b) Silicon zero-background with front press; (c) Slice; (d) Fresh paste with Kapton film.

Thin films: 

  • The PW1813_xx holders used for Si-ZB sample holders can be used. We have 5 units with 32 mm diameter, 16 units with 27 mm diameter and 6 units with 8 mm diameter,
    or
  • Film or solid sample holder between kaptons;
  • HTK-16 chamber for measurements as a function of temperature and
  • Residual Stress Measurements (psi and omega possible settings). Sample stage: ATC-3,
  • Crystallographic texture.  Sample stage: ATC-3,
  • Refletometry.

    Gonio sample stage (Cradle ATC-3)

High-temperature chamber (<1600°C) HTK 16 

Câmara de alta temperatura (até 1600°C) HTK 16 e vista do porta-amostra (filamento de Pt) no interior

  • in situ XRD-measurements up to high temperatures (< 1600°C):
  • Powder samples deposited on the filament (in the form of paste made with solvent)
    • See Appendix E of the manual for how to preserve the filament.
  • Films with/without substrate on the filament (temperature gradient susceptible; thermocouples on stage and movable available).

  Site do fabricante clique aqui