Calorimetric Measurements at Low Temperatures in Toluene Glass and Crystal

TL;DR

This study measures the specific heat of toluene in glass and crystal states at very low temperatures, revealing no evidence of tunneling states and extending existing data to lower temperatures.

Contribution

It provides new low-temperature specific heat data for toluene glass and crystal, and demonstrates a method to prepare bulk toluene glass with minimal ethanol doping.

Findings

No tunneling states detected in toluene glass at studied temperatures.

Low-temperature data aligns with previous studies at moderate temperatures.

Bulk toluene glass prepared with only 2% ethanol doping.

Abstract

The specific heat of toluene in glass and crystal states, has been measured both at low temperatures down to 1.8 K (using the thermal relaxation method) and in a wide temperature range up to the liquid state (using a quasiadiabatic continuous method). Our measurements therefore extend earlier published data to much lower temperatures, thereby allowing to explore the low temperature glassy anomalies in the case of toluene. Surprisingly, no indication of the existence of tunneling states is found, at least within the temperature range studied. At moderate temperatures, our data either for the glass or for the crystal show good agreement with those found in the literature. Also, we have been able to prepare bulk samples of toluene glass by only doping with 2% mol ethanol instead of with higher impurity doses used by other authors.