Purification of Cu by hydrogen plasma-arc zone melting and characterization of trace impurities by secondary ion mass spectrometry

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2008.05.004· OSTI ID:21192590

Lalev, G M ^[1]; Choi, G -S ^[2]; Uchikoshi, M; Mimura, K; Isshiki, M ^[3]

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1. Manufacturing Engineering Centre, Cardiff University, Queen's Building, The Parade, Newport Road, Cardiff CF24 3AA, Wales (United Kingdom)
2. Minerals and Materials Processing Division, Korea Institute of Geoscience and Mineral Resources, 92 Gwahangno, Yuseong-gu, Daejeon 305-350 (Korea, Republic of)
3. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

Purification of 4N (99.99%) and 6N (99.9999%) purity Cu rods by hydrogen plasma-arc zone melting was carried out. Weight loss in the 4N and 6N Cu rods as a function of number of zone refined passes revealed a higher rate of impurity removal by vaporization in 4N Cu when compared to 6N Cu. Purification effect was studied by analyzing major impurities like Mg, Si, Ca, Ti, Cr, Ni and Fe by O{sub 2}{sup +} ions and C, O, As, Cl, P and S by Cs{sup +} ion sources using secondary ion mass spectrometry. A remarkable decrease of Si, Ti and Fe impurity concentrations in Cu at x/L = 0.03 after 10 zone passes was observed, but no similar purification effect along the remaining length of the zone refined copper rod was observed. Mg, Se and Ca in the Cu rods were reduced faster by a high evaporation effect due to P{sub i}/P{sub Cu} > 10{sup 2}. On the other hand, removal of O, C, S and Se was expectedly dominated by vaporization in the form of H{sub 2}O, CH{sub 4,} H{sub 2}S, and H{sub 2}Se through thermodynamically favored reactions. The overall segregation rate of the individual impurity elements was decreased with an increase in the purity from 4N to 6N of Cu rods. SIMS analysis of trace impurities was successfully carried out on HPZM Cu for quantitative estimation.

• OSTI ID: 21192590
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 1 Vol. 60; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CESIUM IONS
COPPER
EVAPORATION
HYDROGEN
IMPURITIES
ION MICROPROBE ANALYSIS
ION SOURCES
MASS SPECTROSCOPY
PLASMA
PURIFICATION
SEGREGATION
ZONE MELTING