We experimentally investigate the thermoelectric power (Seebeck effect) of quasi-two-dimensional single crystals of titanium and zirconium trichalcogenides (TiS 3 , ZrS 3 , ZrSe 3 , and ZrTe 3 ) under applied high pressure up to 10 GPa. Both sulfides were characterized by n-type semiconducting conduction in the whole pressure range investigated and, generally, showed moderate pressure responses of their electronic properties. Metallic ZrTe 3 conserved its p-type conduction under pressure, and its Seebeck coefficient curve displayed a distinct crossover near 2 GPa. Semiconducting ZrSe 3 demonstrated more remarkable responses to applied pressure, which included a multiorder gradual drop in its electrical resistance value up to 9 GPa and an n−p inversion of the dominant conduction type around 6 GPa. Furthermore, we found that a thermoelectric power factor of ZrSe 3 may be greatly improved under high applied pressure, achieving a value of an order of 3.5 mW/(K 2 m) at 9.5 GPa. Thus, an appropriately strained p-type ZrSe 3 with a dramatically reduced band gap value turns to be a promising thermoelectrics. One can anticipate that ZrSe 3 −ZrTe 3 solid solutions, in which the addition of ZrTe 3 should decrease the band gap value of ZrSe 3 in a controlled manner, could also demonstrate high thermoelectric performance parameters. Reversibility and reproducibility of the pressure-driven changes in the electronic properties of ZrSe 3 suggest that it has a potential for other industrial applications linked to cyclic stress loads, for example, in n−p switches or control of p−n−p transistor elements.

The effect of continuous lighting (CL, 24 h) and light spectrum on growth and nutritional quality of arugula (Eruca sativa), broccoli (Brassica oleracea var. italic), mizuna (Brassica rapa. var. nipposinica), and radish (Raphanus sativus var. radicula) were investigated in growth chambers under light-emitting diode (LED) and fluorescent lighting. Microgreens were grown under four combinations of two photoperiods (16 h and 24 h) providing daily light integral (DLI) of 15.6 and 23.3 mol m−2 day−1, correspondingly) with two light spectra: LED lamps and fluorescent lamps (FLU). The results show that fresh and dry weights as well as leaf mass per area and robust index of harvested arugula, broccoli, mizuna, and radish seedlings were significantly higher under CL compared to 16 h photoperiod regardless of light quality. There were no visible signs of leaf photodamage. In all CL-treated plants higher chlorophyll a/b and carotenoid-to-chlorophyll ratios were observed in all plants except mizuna. CL treatment was beneficial for anthocyanin, flavonoid, and proline accumulation. Higher activities of antioxidant enzymes (catalase, superoxide dismutase, ascorbate peroxidase, and guaiacol peroxidase) were also observed in CL-treated plants. In most cases, the effects were more pronounced under LED lighting. These results indicate that plants under mild oxidative stress induced by CL accumulated more non-enzymatic antioxidants and increased the activities of antioxidant enzymes. This added nutritional value to microgreens that are used as functional foods providing health benefits. We suggest that for arugula, broccoli, mizuna, and radish, an LED CL production strategy is possible and can have economic and nutritional benefits.

Erratum: NbS 3 : A unique quasi-one-dimensional conductor with three charge density wave transitions [Phys. Rev. B 95, 035110 (2017)]

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Through transport, compositional and structural studies, we review the features of the chargedensity wave (CDW) conductor of NbS3 (phase II). We highlight three central results: 1) In addition to the previously reported CDW transitions at TP 1 = 360 K and TP 2 = 150 K, another CDW transition occurs at a much higher temperature TP 0 = 620-650 K; evidence for the non-linear conductivity of this CDW is presented. 2) We show that CDW associated with the TP 2 -transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. 3) We show exceptional coherence of the TP 1-CDW at room-temperature. Additionally, we report on the effects of uniaxial strain on the CDW transition temperatures and transport.

An experimental study of the electronic structure of copper intercalated titanium dichalcogenides in a wide range of copper concentrations (x = 0.04-0.8) using x-ray photoelectron spectroscopy, resonant photoelectron spectroscopy, and x-ray absorption spectroscopy has been performed. Shift towards low energies of the Ti 2p and Se 3d core level spectra and a corresponding decrease in the photon energy of Ti 2p absorption spectra with the increase in copper concentration have been found. These sign-anomalous shifts may be explained by the shielding effect of the corresponding atomic shells as a result of the dynamic charge transfer during the formation of a covalent chemical bond between the copper atoms and the TiSe2 matrix.

An experimental study of the electronic structure of VTiSe system in a wide range of vanadium concentrations (x = 0.06-0.9) using x-ray photoelectron spectroscopy and resonant photoelectron spectroscopy has been performed. The partial charge transfer from the VSe to TiSe structural fragments is experimentally observed, and the most part of the charge is localized on the vanadium atoms in the VSe structural fragments.

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