Quantitative texture analysis of polyphased oxides by diffraction: example of Bi2223 sinter-forged ceramic and Y123 foam superconductors

Abstract

This paper deals about the texture analysis of sinter-forging (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+δ (Bi2223) discs and YBa 2 Cu 3 O 7−x (Y123) foams. Orientation distributions were measured by X-ray and neutron diffraction respectively. In the case of Bi2223 samples, an overview of our results is presented. It reflects clearly the importance to combine physical measurements and texture analysis. Several factors as the size of the precursor powder and the process parameters influence significantly the crystallite orientation and consequently the final properties of the textured discs. In the case of Y123 foams, the only usable non destructive diffraction characterisation is the combined approach, and we show what it can bring on one example.

Analysis of the microstructure of superconducting YBCO foams by means of AFM and EBSD

“…EBSD analysis performed on a foam strut taken from position (3) yields in contrast pole figures with a much larger scatter of the 211 orientations, but also here some dominating orientations (maxima) can be found. This situation is similar to that found in the conventional, bulk melt-textured samples [14][15][16][17].…”

“…As a result, 211 particles will be formed in the superconducting matrix, and their behavior may directly influence the growth of the superconducting matrix. This was already studied earlier by us by means of electron backscatter diffraction (EBSD) [14,15] and others employing neutron diffraction [16,17]. The development of the EBSD technique now enables a spatial resolution on ceramic materials which is similar to the atomic force microscopy (AFM) topography measurement [18,19].…”

EBSD study on YBCO textured bulk samples: correlation between crystal growth and ‘microtexture’

“…Figure 8(d) shows the (003) pole figure recalculated from the ODF refined in the Maud software [33,34] using the E-WIMV model [35] and the combined analysis [4]. One pole with a maximum density of 40 m.r.d.…”

Perforated monodomain YBa2Cu3O7−x bulk superconductors prepared by infiltration-growth process

“…2. 10,11 These pole figures clearly illustrate the presence of only one domain present in the sample, with c-axes inclined by approximately 20 • from the normal to the plane of the figures (plane perpendicular to the perforated holes), and a-axes aligned with the main axes of the figure. The texture is single-crystal like, with pole dispersions within 5 • to 10 • of dispersion, at the limit of the refinability of the orientation distribution using our scanning resolution (5 • × 5 • grid).…”