The low-temperature specific heat of thermal reduced graphene oxide
V.V. Sumarokov1, A. Jeżowski2, D. Szewczyk2, A.V. Dolbin1, N.A. Vinnikov1, and M.I. Bagatskii1
1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
2W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences P.O. Box 1410, Wroclaw 50-950, Poland
Received January 9, 2020, published online January 27, 2020
Measurements of heat capacity at constant pressure of thermally reduced graphene oxide (trGO) and graphite oxide (GtO) were performed in the temperature range from 1.8 to 275 K by thermal relaxation method. Above 15 K, the specific heat values of trGO and GtO are close to each other within 20%. Below 10 K, the ratio of the specific heat of trGO to the specific heat of GtO increases with decreasing temperature and reaches 5 at 2 K. It was found that the temperature dependence of the specific heat of trGO is of a complex character. There are temperature ranges in which of the specific heat of trGO is close to either linear or T 2.5.
Key words: graphene oxide, graphite oxide, heat capacity, low-dimensional systems.