Thermal behaviour of cinnabar, α-HgS, and the kinetics of the β-HgS (metacinnabar) - α-HgS conversion at room temperature

Low lattice thermal conductivity and good thermoelectric performance of cinnabar

“…2. Since the phase transition from α-HgS to β-HgS occurs at about 673 K and becomes complete at 698 K [16], we show the values of κ L below 700 K in Fig. 2.…”

“…To date the electronic [17][18][19][20], vibrational [20][21][22][23], optical [24][25][26], luminescence [26,27], photoelectronic [28,29], and photoemission [30] properties of α-HgS have been investigated to an extensive extent. However, the thermal transport and TE properties of α-HgS are not yet known, although the characters of thermal expansion and specific heat were once reported [16,20]. In this paper, we systematically investigate the thermal and electronic transport properties of α-HgS and conclude that this material possesses low lattice thermal conductivity κ L and high power factor S 2 σ .…”

“…Meanwhile, its polymorph, metacinnabar (β-HgS, a zincblendelike configuration), is also found in nature, and can be grown experimentally through adding traces of iron (∼1%) to the elements utilized in the growth. For pure α-HgS samples, the phase transition to β-HgS occurs at about 673 K and becomes complete at 698 K due to the kinetics reasons [16]. While β-HgS is a zero-gap semimetal, α-HgS is an anisotropic semiconductor with a large band gap and highly dichroic character of the absorption coefficient, which thus makes it be an interesting material.…”

Degradation of Vermilion Red Color in Oil and Mural Paintings: A Comparative Applied Study

“…Then, it was used by ancient Greeks between the third and fourth centuries BC. It has become scarcer since the mid-first century AD [1]. Vermillion was used in classic mural paintings in Bombay, in the mural paintings of the Gothic Church in the Monastery of Pedralbes in 1326 AD in Spain, and Love of the Mag oil painting by Robbins (1577-1640 AD) at the Royal Museum of Fine Arts in Antwerp [2].…”

“…The interaction mechanism continues in the light until the color degradation occurs completely. Damage depends on the presence of air pollutants [14]. After exposure to the light, chlorine is a catalyst for chemical photo oxidant reaction [15], the á -Cinnabar changes to mineral mercury and sulfur, then chlorine ion interacts with the mineral mercury and the mercury chloride, and the ion chlorine interacts with cinnabar to give sulfur (S) and corderoite (Hg 3 S 2 Cl 2 ) that is converted to calomel.…”