Table 2. Onset Temperature and Enthalpy for the Solid–Solid Phase Transition and Depression in the Melting Temperature.

	Tonset, solid–solid	ΔT solid–solid	ΔHsolid–solida	ΔTm	ΔHma
sample	K	K	kJ/mol	K	kJ/mol
SiO2-3.3	337.7	48.9	1.29	103	1.54
SiO2-3.6	337.0	49.6	0.66	102	0
SiO2-4.2	354.7	32.0	1.52	85	1.79
SiO2-4.4	353.0	33.6	1.23	81	2.03
SiO2-5.9	359.0	27.6	1.70	61	1.12
SiO2-6.1	364.4	22.2	1.80	45	1.20
C-3.1	360.0	26.6	1.27	71	1.35
C-3.8	367.7	18.9	1.77	53	2.63
C-5.6	373.7	12.9	2.37	35	4.27
C-20	382.4	4.25	2.98	18	3.91
mc LiBH4b	386.6	0	4.18	0	7.60

^aThe enthalpies were calibrated using macrocrystalline (mc) LiBH₄ as a reference.

^bTheoretical ΔH values were taken from the literature.²⁴ The raw data measured values were 2.26 and 4.60 kJ/mol for the solid–solid transition and melting, respectively