Full reciprocal-space mapping up to 2000 K under controlled atmosphere: the multipurpose QMAX furnace

Abstract

A furnace that covers the temperature range from room temperature up to 2000 K has been designed, built and implemented on the D2AM beamline at the ESRF. The QMAX furnace is devoted to the full exploration of the reciprocal hemispace located above the sample surface. It is well suited for symmetric and asymmetric 3D reciprocal space mapping. Owing to the hemispherical design of the furnace, 3D grazing-incidence small-and wide-angle scattering and diffraction measurements are possible. Inert and reactive experiments can be performed at atmospheric pressure under controlled gas flux. It is demonstrated that the QMAX furnace allows monitoring of structural phase transitions as well as microstructural evolution at the nanoscale, such as self-organization processes, crystal growth and strain relaxation. A time-resolved in situ oxidation experiment illustrates the capability to probe the high-temperature reactivity of materials. research papers J. Appl. Cryst. (2020). 53, 650-661 René Guinebretière et al. The multipurpose QMAX furnace 651 research papers J. Appl. Cryst. (2020). 53, 650-661 René Guinebretière et al. The multipurpose QMAX furnace 659

Coupling between elastic strains and phase transition in dense pure zirconia polycrystals

“…The first observation concerns the strong anisotropy of the thermal expansion of monoclinic zirconia. Indeed, in agreement with previous results obtained on pure zirconia powders [28,29], during heating the value of the b cell parameter is quasi-independent of the temperature and only a slight evolution is observed during the cooling. Most of the previously published papers related to zirconia thermal expansion concern bulk or powdered materials made of doped zirconia, and because of the presence of residual stresses, different values of thermal expansion are expected for different samples.…”

“…A volume of matter corresponding to the area observed in Fig. 1(a) and, thus, to a unique parent cubic crystal constitutes an ideal sample allowing the evaluation of the impact on the SPT of elastic strains generated by the successive SPTs associated with the volume variations and with the anisotropic thermal expansion of monoclinic zirconia [28,29]. We recently determined the strain distribution in such samples using a local x-ray microdiffraction method [27,30].…”

“…On the experimental point of view, the key point was to be able to record the diffraction patterns in situ at temperatures high enough to promote the m → t SPT of all the zirconia crystals. For that purpose, we used the QMAX furnace installed on the D2AM beamline which allows for the realization of x-ray scattering experiments at temperatures up to 1700°C [29]. The bulk samples were put on the top of the furnace, which is designed in such a way that all the diffuse or diffracted x-ray beams emitted in the half space above the sample surface can be recorded by the detector.…”

“…This allows the well-known sample displacement problem to be solved [40]. More information concerning this procedure can be found in [29].…”

Huge local elastic strains in bulk nanostructured pure zirconia materials

“…It means that all these monoclinic submicrometric crystals of one given area are in fact belonging to crystallographic variants of the same cubic grain generated by the successive SPTs occurring during the cooling of the sample. We show in this article by X-ray Laue microdiffraction that the successive SPTs associated with volume variation and anisotropic thermal expansion of monoclinic zirconia [26,27] induce local strains of a few percent into the pure zirconia crystals. Associated internal stresses are in the GPa range.…”