Influence of the Shape of Copper Powder Particles on the Crystal Structure and Some Decisive Characteristics of the Metal Powders

Abstract

Three different forms of Cu powder particles obtained by either galvanostatic electrolysis or a non-electrolytic method were analyzed by a scanning electron microscope (SEM), X-ray diffraction (XRD) and particle size distribution (PSD). Electrolytic procedures were performed under different hydrogen evolution conditions, leading to the formation of either 3D branched dendrites or disperse cauliflower-like particles. The third type of particles were compact agglomerates of the Cu grains, whose structural characteristics indicated that they were formed by a non-electrolytic method. Unlike the sharp tips that characterize the usual form of Cu dendrites, the ends of both the trunk and branches were globules in the formed dendrites, indicating that a novel type of Cu dendrites was formed in this investigation. Although the macro structures of the particles were extremely varied, they had very similar micro structures because they were constructed by spherical grains. The Cu crystallites were randomly oriented in the dendrites and compact agglomerates of the Cu grains, while the disperse cauliflower-like particles showed (220) and (311) preferred orientation. This indicates that the applied current density affects not only the morphology of the particles, but also their crystal structure. The best performance, defined by the largest specific surface area and the smallest particle size, was by the galvanostatically produced powder consisting of disperse cauliflower-like particles.

Morphology, Structure and Mechanical Properties of Copper Coatings Electrodeposited by Pulsating Current (PC) Regime on Si(111)

“…Please note that the XRD pattern obtained with the current density amplitude of 100 mA·cm −2 ( Figure 5) is given again and corresponds to that obtained with a frequency of 100 Hz in Figure 4. The XRD maximum obtained at 2θ angles of 43.3 • , 50.4 • , 74.1 • and 89.9 • belong to the (111), (200), (220) and (311) crystal planes, confirming the face-centered cubic (FCC) crystal lattice of Cu [41]. Aside from the Cu coating obtained at a frequency of 30 Hz, in all other XRD patterns, Cu crystallites were predominantly oriented in the (111) plane.…”

“…The preferred orientation of Cu coatings was estimated by determining the "Texture Coefficient", TC(hkl) and the "Relative Texture Coefficient", RTC(hkl) [39][40][41]. The procedure for the determination of these coefficients is described in Appendix B.…”

“…In the XRD pattern of the Cu coating electrodeposited with a frequency of 30 Hz, the predominant orientation of Cu crystallites in the (220) crystal plane was observed. The preferred orientation of Cu coatings was estimated by determination of the "Texture Coefficient" (TC(hkl)) and "Relative Texture Coefficient" (RTC(hkl)) [40,41]. It is necessary to note that the TC(hkl) values larger than 1.00 indicate the existence of the preferred orientation in the (hkl) plane.…”

“…It is necessary to note that the TC(hkl) values larger than 1.00 indicate the existence of the preferred orientation in the (hkl) plane. Simultaneously, since four reflections in the 2θ range between 30 • and 95 • were recorded, the values of RTC(hkl) coefficients larger than 25% indicate the existence of the preferred orientation [40,41].…”

“…The ratio of reflection intensity (hkl) to the sum of all intensities of the recorded reflections, R (hkl), (in %) is given by Equation (A8) [39][40][41]:…”