The system Ga-Ni: A new investigation of the Ga-rich part

Autor(en)
Clemens Schmetterer, Hans Flandorfer, Christian Lengauer, J -P Bros, Herbert Ipser
Abstrakt

A new version of the Ga-Ni phase diagram was established based on the investigation of ten samples in the Ga-rich part by DTA, powder X-ray diffraction and EPMA. Two significant differences compared to the last version of the phase diagram were discovered. The most Ga-rich compound Ga4Ni was not found as such. Instead the existence of Ga7Ni3, as already described earlier in literature, was confirmed. Furthermore, the peritectic reaction GaNi + L ? Ga3Ni2 was found at a temperature of 950 °C, which is more than 50 °C higher than the indicated literature value. At 80 at.% Ga, additional lines in the X-ray powder patterns, which were also reported in literature, suggest the presence of a further, possibly metastable Ga-rich phase. Although no single-crystal X-ray diffraction measurements could be performed, the Ga-rich phase could be characterized using a Ga5Pd type crystal structure including a refinement of the atomic parameters. The partial and integral enthalpies of mixing of liquid Ga-Ni alloys were determined at various temperatures (1031, 1134, 1246, 1261, 1321, 1388 °C) using a drop calorimetric technique. No significant temperature dependence of ?mixH could be observed. The minimum was found at 52 at.% Ni with a value of -35 kJ/mol.

Organisation(en)
Institut für Funktionelle Materialien und Katalyse, Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Université de Provence Aix-Marseille I
Journal
Intermetallics
Band
18
Seiten
277-285
Anzahl der Seiten
9
ISSN
0966-9795
DOI
https://doi.org/10.1016/j.intermet.2009.07.024
Publikationsdatum
2010
Peer-reviewed
Ja
ÖFOS 2012
104003 Anorganische Chemie, 105113 Kristallographie, 104011 Materialchemie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/71ae0bb6-bd81-4919-a76d-3fb383e7c312