Specific heat of Zr65Al7.5Cu17.5Ni10 around the glass transition
Institut für Physik, Universität Augsburg,
Universitätsstrasse 1, 86135 Augsburg, Germany
Accepted: 31 August 1998
Published online: 15 February 1999
Dynamic calorimetric measurements are performed for the quaternary metallic glass Zr65Al7.5Cu17.5Ni10 in order to analyse the dependence on different heating rates for the glass transition temperature Tg. We compare two different temperature programs used for sample relaxation, to estimate the influence of the thermal history on Tg. A lower limit for the glass transition temperature Tg was calculated according to two different models based on the fact, that width and temperature of the glass transition depend on the experimental time scale set by the heating rate: One model assumes a Vogel-Fulcher-Tammann type behaviour, as used to describe more or less "fragile" glass formers and the other assumes an Arrhenius-like behaviour, which is related to "strong" glass formers. The values obtained from both models differ by about 80K. From additional absolute specific heat capacity measurements we calculate the Kauzmann temperature TK, as a lower limit for the temperature of the glass transition from thermodynamic aspects. Comparing TK with the temperature values obtained from the two evaluation models we can classify the quaternary metallic glass Zr65Al7.5Cu17.5Ni10, to behave more like a "strong" glass former.
PACS: 81.05.Kf – Glasses (including metallic glasses) / 64.70.Pf – Glass transitions / 81.70.Pg – Thermal analysis, differential thermal analysis (DTA), differential thermogravimetric analysis
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999