Journal of Applied Crystallography
0021-8898
1600-5767
Anh Quốc
Cơ quản chủ quản: International Union of Crystallography , INT UNION CRYSTALLOGRAPHY
Lĩnh vực:
Biochemistry, Genetics and Molecular Biology (miscellaneous)
Phân tích ảnh hưởng
Thông tin về tạp chí
Many research topics in condensed matter research, materials science and the life sciences make use of crystallographic methods to study crystalline and non-crystalline matter with neutrons, X-rays and electrons. Articles published in Journal of Applied Crystallography focus on these methods and their use in identifying structural and diffusion-controlled phase transformations, structure-property relationships, structural changes of defects, interfaces and surfaces, etc. Developments of instrumentation and crystallographic apparatus, theory and interpretation, numerical analysis and other related subjects are also covered. The journal is the primary place where crystallographic computer program information is published.
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Preparation and microstructure characterization of ball-milled ZrO<sub>2</sub>powder by the Rietveld method: monoclinic to cubic phase transformation without any additive The phase transformation kinetics of high-energy ball-milled monoclinic ZrO2 have been studied in detail by Rietveld powder structure refinement analysis. In the present study, no stabilizing compound was required to obtain the cubic phase. The fine-grain powder was milled in a planetary ball mill for up to several hours at different BPMRs (ball to powder mass ratios): 10:1, 20:1, 35:1 and 40:1. During the process of ball milling, the monoclinic phase is gradually transformed to the cubic phase. The relative phase abundances of the respective phases, the particle sizes, the r.m.s. strains, the lattice parameter changes,etc. , have been estimated from Rietveld analysis of X-ray powder diffraction data. It has been found that a higher BPMR exerts more influence on rapid phase transformation. In them - toc -ZrO2 phase transformation, no formation of an intermediate tetragonal ZrO2 phase has been found. The small change in the lattice volume ofm -ZrO2 , which is very close to the lattice volume ofc -ZrO2 , caused by ball milling may be attributed to this phase change. The formation of thec phase is noticed, in general, after just 1 h of ball milling, and the particle size of them phase is reduced to a large extent at the first stage of milling and remains almost unchanged with increasing milling time. However, the particle size of thec phase increases with increasing milling time for the samples milled with higher BPMRs (35:1 and 40:1), suggesting that quenching caused by a high impact energy followed by an annealing effect may play a vital role, which is further manifested in the agglomeration of small particles.
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