6533b833fe1ef96bd129b5d0

RESEARCH PRODUCT

Temperature dependence of the static structure factor of ortho-terphenyl in the supercooled liquid regime close to the glass transition

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Abstract Studying the temperature dependence of the static structure factor of ortho-terphenyl from the liquid state down to the glass we find that the main peak of S ( Q ) is split into two maxima which behave quite differently. While the maximum at Q =1.4 A −1 is not much affected by the temperature variation the one at 1.9 A −1 is significantly enhanced. This effect is connected with a change of the short range order, i.e. of the intermolecular distances, but evolves continuously. Thus the dynamic anomalies that have been observed in this system around a characteristic temperature T c ≈290 K are not simply due to a discontinuous change in S ( Q ) but can be attributed to the existence of a critical singularity in the dynamical behaviour at T c as predicted by mode coupling theory.