Phase, Microstructure, Thermochromic, and Thermophysical Analyses of Hydrothermally Synthesized W-Doped VO₂ Nanopowder

Table 2

Thermochromic properties of undoped and W-doped samples.

Sample	W conc. (wt%)	Phase transition (°C)			h (C°)	Enthalpy (J/g)
		τheat	τcool	τc		ΔHheat	ΔHcool	ΔH
VMW0%	0	66.01	66.93	66.47	0.92	−53.77	54.22	54.00
VMW1%	1	57.24	62.05	59.65	4.81	−33.68	32.48	33.08
VMW1.5%	1.5	54.46	59.47	56.97	5.01	−35.24	36.46	35.85
VMW2%	2	51.62	61.71	56.67	10.09	−44.96	44.75	44.86
VMW3%	3	31.64; 51.99	58.41	47.35	6.42	−10.52;−37.47	38.67	28.89

τ_c = (τ_heat + τ_cool)/2, h = |τ_heat - τ_cool|, and ΔH = (|ΔH_heat| + ΔH_cool)/2.