NiI₂ (Nickel Diiodide)

NiI₂ is a layered transition-metal halide and a type-II multiferroic (magnetically induced ferroelectric). At low temperature it develops a helical (proper-screw) spin structure whose non-collinear order breaks inversion symmetry and induces an electric polarization, directly coupling magnetism and ferroelectricity; this multiferroic behavior persists down to the monolayer, making NiI₂ one of the few materials that remain multiferroic in the two-dimensional limit. These features make it a prominent material for research on 2D multiferroics, magnetoelectric coupling, and spintronics.

Growth method: Chemical vapor transport (CVT).

Sample specifications: Individual crystals measure approximately 3 mm, with a purity of up to 99.9999% (6N), and multiple high-quality single-crystal pieces included in each package.

Exfoliation: Easy — readily cleaved into thin flakes by standard mechanical exfoliation.