Table 1.

Specific heat coefficients

Sample state	cTLS (μJ/g·K2)	cD (μJ/g·K4)	cDelas (μJ/g·K4)
Crystal	––	15.0 ± 0.3	––
Conventional glass	13.7 ± 0.3	49.4 ± 0.2	51
USG-1	0.2 ± 0.9	46.4 ± 0.6	41
USG-2	0.02 ± 0.8	36.9 ± 0.4	41
Degraded USG	13.0 ± 0.7	40.6 ± 0.5	––

Coefficients and statistical errors from the least-squares linear fits at low temperatures to the function C_P = c_TLS·T + c_D·T ³ (Fig. 2B). The last column indicates the expected Debye coefficient c_D^elas for conventional and USGs of IMC, obtained from published elastic data at room temperature (24).