Crystal structure determinations of two niobium dichalcogenides (3R- Nb 1.09S 2 and 2H-NbSe 2) are reported: the sulfide compound that crystallizes in the R3m space group (a = 3.3297(6) , c = 17.869(5) ) has been refined to a R F value of 2.63%, while the selenide compound ...
The two Tc maxima in the double-dome appear at the critical doping, where CDW orders vanish similar to 1T-Se2 and 2H-NbSe2.25, 26 DISCUSSION It should be noted that electron-irradiated 2H-TaSe2 shows enhancement of superconducting Tc up to about 2.5 K.27 Irradiation introduces defects, i....