NiTe2(Nickel Telluride)

Bulk nickel ditelluride (NiTe₂) is a typical transition-metal dichalcogenide (TMD) with a stoichiometric ratio of 1:2, classified as a layered metallic compound. It crystallizes in the CdI₂-type structure (space group P-3m1, No. 164), where each Ni atom is octahedrally coordinated by six Te atoms, forming Te–Ni–Te sandwich-like layers stacked together via van der Waals interactions.

In appearance, bulk NiTe₂ exhibits a silvery-gray metallic luster and shows excellent electrical conductivity and thermal stability.

Electronic-structure studies reveal that NiTe₂ possesses a distinct band crossing near the Fermi level, exhibiting metallic behavior with an approximately zero band gap (~0 eV). Both theoretical calculations and angle-resolved photoemission spectroscopy (ARPES) measurements identify NiTe₂ as a topological semimetal, featuring Dirac-type linearly dispersing band crossings around the Fermi energy. Moreover, its electronic bands are strongly affected by spin–orbit coupling (SOC), leading to phenomena such as an anomalous Hall effect (AHE) and anisotropic magnetotransport at low temperatures.

Bulk NiTe₂ demonstrates high chemical and environmental stability, maintaining its structural integrity under ambient conditions, with a thermal decomposition temperature above 400 °C. Owing to its excellent conductivity, topological electronic characteristics, and robustness, NiTe₂ holds significant potential for applications in topological quantum materials, spintronics, electrocatalysis (e.g., hydrogen evolution reaction, HER), and as a substrate or component in two-dimensional heterostructures.