The effect of Sn intercalation on the superconducting properties of 2H NbSe2

Abstract

2H-NbSe 2 is known to be an archetype layered transitional metal dichalcogenide superconductor with a superconducting transition temperature of 7.3 K.In this article, we investigate the influence of Sn intercalation on superconducting properties of 2H-NbSe 2 . Sn being nonmagnetic and having no outer shell d-electronsunlike transition metals, one naively would presume that its effect on superconducting properties will be very marginal. However, our magnetic and transport studies reveal a significant reduction of both superconducting transition temperature and upper critical field [T c and B C2 (0)] upon Sn intercalation. With a mere 4 mole% Sn intercalation, it is observed that T c and B C2 (0) get suppressed by ~3.5K and 3T, respectively. Werthamer-Helfand-Hohenberg (WHH) analysis of magneto-transport data is performed to estimateB C2 (0). From the low temperature Raman scattering data in the normal phase of intercalated NbSe 2 , it is inferred that the suppression of superconductivity cannot be ascribed to strengthening of charge density wave (CDW)ordering. The effects such as electron-doping induced Fermi surface change and/or disorder scattering upon intercalation are speculated to be at play for the observed phenomena.

Nominal Effect of Mg Intercalation on the Superconducting Properties of 2H–NbSe2

“…The estimated H c1 (0) for 2H–NbSe 2 is found to be ∼155 Oe which is close to the values observed in an earlier report . However, with the intercalation of Mg, H c1 (0) sharply reduces to ∼75 Oe for x = 0.02, and a further increase in x gradually reduces H c1 (0) down to ∼45 Oe for x = 0.1.…”

“…Intercalation in 2H–NbSe 2 always leads to an increase in the c -lattice parameter; however, the extent of increase depends on the nature of intercalant. For example, 4 mol % of Sn intercalation in 2H–NbSe 2 led to an increase in the c -lattice parameter by ∼0.03 Å, while 2.5 mol % of Rb intercalation results in an increase in the c -lattice parameter by ∼0.035 Å . Although Cu has a comparable size as that of Mg, upon intercalation of 9 mol % leads to an increase in the c -lattice parameter of ∼0.06 Å .…”

“…Different types of intercalating species can have different effects on the structure and electronic properties of LMs. 2H–NbSe 2 has been intercalated with different types of moieties such as alkali metals, − transition metals, − p-block metals, − and organic molecules, and their effect on T c has been studied. In most of the cases, intercalation of different moieties in 2H–NbSe 2 leads to the suppression of T c .…”

“…Therefore, a complete understanding of the factors that affect the T c of intercalated 2H–NbSe 2 requires further investigation with varying types of intercalants. In our previous paper, we have reported the effect of Sn intercalation on the superconductivity of 2H–NbSe 2 , where T c decreases sharply from 6.3 to 3.1 K (2H–NbSe 2 and Sn 0.04 NbSe 2 ) with the increase in the Sn amount and is related to the increase in the c -lattice parameter . To further explore the effect of other types of intercalant on T c , we have synthesized and studied the superconducting properties of Mg-intercalated 2H–NbSe 2 .…”

The effect of the metal and selenium precursors on the properties of NbSe2and Nb2Se9nanostructures and their application in dye-sensitized solar cells

“…The NbSe 2 spectrum has two characteristic peaks, the out of plane A 1g peak and the in plane E 2g peak at 225 and ∼245 cm −1 , respectively. 26 On the other hand, the vibrational modes of Nb 2 Se 9 were at 239.62 cm −1 due to two Nb atoms vibrating along the (101) plane and the two Se pairs with a stretching motion. 27 The second vibrational motion at 284.18 cm −1 was due to two pairs of stretching Nb atoms crossed and all the Se atoms vibrating in the outward direction at the same time.…”